This document provides an introduction to pulse repetition interval (PRI) analysis and deinterleaving from an electronic intelligence (ELINT) perspective. It discusses key concepts such as PRI, unambiguous range and velocity, range-velocity ambiguity, optimum PRI for medium PRF radars, and PRI stagger. The document explains how understanding radar constraints such as range resolution, integration time limits, Doppler resolution, and frequency agility can help an ELINT analyst correctly interpret radar signals and anticipate signal characteristics.
10 range and doppler measurements in radar systemsSolo Hermelin
Present method of Range and Doppler measurement in a RADAR system.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Recommend to view this presentation on my website in power point.
Analysis for Radar and Electronic WarfareReza Taryghat
This document discusses techniques for measuring pulsed RF signals used in radar and electronic warfare applications. It begins with an overview of common radar applications and measurement types. It then discusses tools for measuring pulse parameters like pulse width, repetition interval, and power. These tools include power meters, oscilloscopes, spectrum analyzers, and specialized pulse analyzers. It also covers vector signal analysis and its ability to analyze modulation embedded on pulses. The rest of the document provides examples of measuring pulses with these various tools and techniques like pulse building, frequency hopping analysis, and analyzing LFM chirps.
This document provides an overview of radar systems. It discusses what radar is, the evolution of radar from its initial uses detecting objects with radio waves in the late 1800s. It then explains the basic principles of how radar works to detect objects using radio signal transmission and reflection. Key components of radar systems like transmitters, receivers, antennas and signal processing are described. Applications of radar systems include military, remote sensing, air traffic control, and navigation. The document also discusses radar modulators and antenna design considerations for radar.
Describes Signal Processing in Radar Systems,
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://solohermelin.com.
I recommend to see the presentation on my website under RADAR Folder, Signal Processing Subfolder.
An active phased array radar system uses a digital beamforming architecture with transmit/receive modules behind each radiating antenna element. This distributed amplifier approach improves noise figure and clutter attenuation compared to passive arrays. Digital beamforming allows formation of multiple simultaneous beams and improved dynamic range. Dual polarized arrays can operate in different modes like alternating transmit and simultaneous receive to measure linear depolarization ratios. Future trends include integrating more components into the antenna and using wideband semiconductor devices.
Radar 2009 a 14 airborne pulse doppler radarForward2025
This document provides an overview of a lecture on airborne pulse Doppler radar systems. It discusses different airborne radar missions including fighter/interceptor radars like those used on F-16s and F-35s, as well as airborne early warning radars like AWACS. It covers topics like airborne radar clutter, pulse Doppler modes using different PRFs, and examples of military radars and their specifications. The goal is to explain the considerations and techniques involved in airborne pulse Doppler radar system design and operation.
This document provides a summary of a professional development short course on ELINT (Electronic Intelligence) Interception and Analysis. The course, taught by Dr. Richard G. Wiley, covers methods for intercepting radar and other non-communication signals, analyzing the signals to determine their functions and capabilities, and practical exercises. Participants receive a textbook on ELINT. The 4-day course outline covers topics like radar fundamentals, receiver types, direction finding techniques, emitter location, pulse analysis, and modern radar waveforms.
10 range and doppler measurements in radar systemsSolo Hermelin
Present method of Range and Doppler measurement in a RADAR system.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://www.solohermelin.com.
Recommend to view this presentation on my website in power point.
Analysis for Radar and Electronic WarfareReza Taryghat
This document discusses techniques for measuring pulsed RF signals used in radar and electronic warfare applications. It begins with an overview of common radar applications and measurement types. It then discusses tools for measuring pulse parameters like pulse width, repetition interval, and power. These tools include power meters, oscilloscopes, spectrum analyzers, and specialized pulse analyzers. It also covers vector signal analysis and its ability to analyze modulation embedded on pulses. The rest of the document provides examples of measuring pulses with these various tools and techniques like pulse building, frequency hopping analysis, and analyzing LFM chirps.
This document provides an overview of radar systems. It discusses what radar is, the evolution of radar from its initial uses detecting objects with radio waves in the late 1800s. It then explains the basic principles of how radar works to detect objects using radio signal transmission and reflection. Key components of radar systems like transmitters, receivers, antennas and signal processing are described. Applications of radar systems include military, remote sensing, air traffic control, and navigation. The document also discusses radar modulators and antenna design considerations for radar.
Describes Signal Processing in Radar Systems,
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://solohermelin.com.
I recommend to see the presentation on my website under RADAR Folder, Signal Processing Subfolder.
An active phased array radar system uses a digital beamforming architecture with transmit/receive modules behind each radiating antenna element. This distributed amplifier approach improves noise figure and clutter attenuation compared to passive arrays. Digital beamforming allows formation of multiple simultaneous beams and improved dynamic range. Dual polarized arrays can operate in different modes like alternating transmit and simultaneous receive to measure linear depolarization ratios. Future trends include integrating more components into the antenna and using wideband semiconductor devices.
Radar 2009 a 14 airborne pulse doppler radarForward2025
This document provides an overview of a lecture on airborne pulse Doppler radar systems. It discusses different airborne radar missions including fighter/interceptor radars like those used on F-16s and F-35s, as well as airborne early warning radars like AWACS. It covers topics like airborne radar clutter, pulse Doppler modes using different PRFs, and examples of military radars and their specifications. The goal is to explain the considerations and techniques involved in airborne pulse Doppler radar system design and operation.
This document provides a summary of a professional development short course on ELINT (Electronic Intelligence) Interception and Analysis. The course, taught by Dr. Richard G. Wiley, covers methods for intercepting radar and other non-communication signals, analyzing the signals to determine their functions and capabilities, and practical exercises. Participants receive a textbook on ELINT. The 4-day course outline covers topics like radar fundamentals, receiver types, direction finding techniques, emitter location, pulse analysis, and modern radar waveforms.
Radar 2009 a 19 electronic counter measuresForward2025
This document contains slides from a lecture on electronic countermeasures (ECM) against radar systems. It discusses how ECM techniques like chaff, noise jamming and random pulses can be used to mask targets from radar detection by increasing clutter. It provides details on how chaff works, including its reflectivity properties and how it is dispensed. Examples are given of chaff masking an aircraft and deceiving trackers. The presentation also introduces how electronic counter-countermeasures (ECCM) can be used to counter ECM techniques.
The document discusses different types of radar systems and their components and principles of operation. It covers topics like pulse radar vs continuous wave radar, components of each type of system like transmitter, receiver, antennas, and how factors like pulse width, repetition frequency and power affect radar performance and capabilities. It also discusses modulation techniques, antenna beam formation, and different types of radar displays.
This document discusses continuous wave (CW) radar and frequency modulated continuous wave (FMCW) radar. It defines radar as an electromagnetic device that can detect objects hidden from view using radio waves. Radar is classified into primary types including CW and modulated radar. CW radar uses the Doppler effect to detect moving targets based on changes in transmitted frequency. However, CW radar cannot determine range. FMCW radar modulates the transmitted frequency over time and compares the received frequency to determine both range and radial velocity of targets. Key applications of radar include military surveillance, weather monitoring, air traffic control and more.
Radar is a system that uses radio waves to detect objects by transmitting electromagnetic waves and analyzing the reflected signals. It consists of a transmitter that generates radio waves, a receiver to detect the reflected waves, and an antenna to transmit and receive the signals. Radar can determine attributes of detected objects such as range, angle, or velocity. It has numerous military and civilian applications including air traffic control, weather monitoring, vehicle speed detection, and space exploration. The Indian Army employs various radar systems like the Rohini, Rajendra, Indra, and Swordfish radars to detect threats. Radar remains an important detection technology due to its all-weather capabilities and ability to sense objects day or night through cloud cover.
This White Paper provides a general overview of various military and commercial radar systems. It also covers some typical measurements on such systems and their components.
Learn more about Radar Component Testing here: https://www.rohde-schwarz.com/solutions/test-and-measurement/aerospace-defense/radar-ew-test/radar-component-testing/radar-component-testing_250800.html
Radar uses radio waves to detect objects and determine their range, direction, and speed. It works by transmitting pulses of radio waves and receiving the echoes bounced back from objects. The time delay between transmission and reception is used to calculate distances to targets. Doppler radar uses the Doppler effect of radio waves to detect how fast targets are moving based on changes in frequency of the echoes.
This document provides an overview of radar cross section (RCS) and techniques for predicting a target's RCS through both measurement and theoretical calculation. It begins with definitions of RCS and factors affecting it. Examples of typical RCS values for different targets are given. Physical scattering mechanisms and contributors to a target's RCS are described. Both full-scale and scale model target measurement techniques are outlined. Theoretical prediction methods including geometrical optics, physical optics, and diffraction theories are introduced. Scaling laws for applying results from scale models to full-scale targets are also covered.
RADAR stands for Radio Detection and Ranging. It uses electromagnetic waves to detect objects like aircraft, ships, vehicles, weather formations and terrain by determining their range, altitude, direction or speed. The basic principles of radar involve transmitting pulses and measuring their time of return to determine characteristics of detected objects like distance, direction and elevation angle. Interference from noise, clutter and jamming can reduce radar detection capabilities.
Radar was originally developed for military purposes during World War 2 to detect ships and airplanes. Scientists later discovered that radar could also detect precipitation, making it an essential tool for weather prediction. There are two main types of radar: pulse radar which uses pulse transmission to determine range and continuous wave radar which relies on the Doppler effect. Key radar components include the transmitter, receiver, antenna, and display unit. Radar systems can be classified by their primary mission as search, tracking, or weather surveillance radars. Common examples include air search radars, long range surveillance radars, and tracking radars used in aircraft.
Radar 2009 a 12 clutter rejection basics and mtiForward2025
This document contains lecture slides about radar clutter rejection techniques. It discusses the history of moving target indication (MTI) and how digital technology has enabled more advanced processing. MTI uses Doppler filtering to suppress stationary clutter and detect moving targets. Early MTI employed crude subtraction of stored pulses. Modern digital implementations allow complex signal processing over many pulses for improved clutter cancellation.
RADAR stands for Radio Detection and Ranging. It uses radio waves to determine the range, altitude, direction or speed of objects. The document discusses the basic principles and components of radar systems. It describes how pulsed radar works by transmitting pulses and calculating distance based on time of flight. Continuous wave radar is also covered, which can determine velocity using Doppler shift. Applications discussed include navigation, weather monitoring, air traffic control and military uses such as early warning systems and missile guidance.
RADAR stands for Radio Detection and Ranging. It uses electromagnetic waves to detect the position, velocity, and characteristics of targets. RADAR was originally developed for military purposes during World War 2, when it was used by the British and US militaries to locate ships and airplanes. Today, RADAR is an essential tool for weather prediction and analysis. Different types of RADAR include pulse transmission RADAR and continuous wave RADAR. RADAR comes in various forms such as search RADAR for detection and tracking RADAR for following individual targets. The frequency used depends on the desired range, with lower frequencies allowing longer detection distances.
Radar 2009 a 15 parameter estimation and tracking part 1Forward2025
The document discusses a lecture on parameter estimation and tracking in radar systems. It covers topics like observable estimation including range, angle, Doppler, and amplitude measurement accuracy. It also discusses single target tracking techniques such as amplitude monopulse, phase comparison monopulse, sequential lobing, and conical scanning. The outline indicates it will cover multiple target tracking and provide a summary. Diagrams are included to illustrate concepts like angular tracking error sources and Doppler estimation.
This document provides an overview of software-defined radio (SDR), including its definition, history, advantages, technical overview, and architecture. SDR is defined as a radio system where components typically implemented in hardware, such as mixers and filters, are instead implemented through software. The term was coined in 1991, with an early military project in 1992. SDR provides advantages like complete digital baseband processing and faster software prototyping. Its technical overview describes ideal SDR components and practical implementations using digital signal processing and field-programmable gate arrays.
WE3.L10.2: COMMUNICATION CODING OF PULSED RADAR SYSTEMSgrssieee
The document discusses using OFDM signals for both radar detection and communication. It proposes a system called "RadCom" that uses coded OFDM signals to achieve high data rates for communication payloads while also providing high processing gain for radar functions like range and velocity detection. Key advantages of OFDM signals for this joint system include robust modulation for communications, the ability to do Doppler processing, and potential for digital beamforming to improve angular resolution. Simulations and measurements demonstrate the feasibility of OFDM signals to achieve both radar imaging and binary data transfer with a single transmission.
Working Processes Of Radar
History – Before Radar
Principle Of Operation
Radio Detection And Ranging
Radar Functions
Radar Bands And Usage
Terminology Of Radar Systems
Radar Range Equation
Types Of Radar
Pulse RADAR
Duplexer Using Pin Switches
Doppler Effect
Principle Of Continuous Wave Radar
Principles Of MTI RADAR
Different Types Of RADAR & It’s Applications
This document provides an overview of key concepts in radio frequency (RF) technology for wireless communication systems. It defines terms like dBm for measuring power, and modulation schemes like amplitude shift keying (ASK), frequency shift keying (FSK), and phase shift keying (PSK) for encoding digital signals onto radio carriers. The document also outlines considerations for selecting an appropriate low-power wireless solution, including radio spectrum and network types.
Radar 2009 a 16 parameter estimation and tracking part2Forward2025
This document summarizes a lecture on parameter estimation and tracking. It discusses tracking processes like track association, initiation, maintenance through prediction and updating, and termination. Filtering techniques like the Kalman filter are presented as ways to estimate target position and velocity while accounting for noise and maneuvers. Examples of civilian and military target maneuvers are provided to illustrate the challenges of tracking.
This document provides an introduction to electronic warfare analyses. It discusses definitions of ELINT and EW terminology. It also covers topics like ELINT collection cycles, RF receiver characteristics, direction finding analysis, scan pattern analysis, and PRI analysis. The document puts these concepts together using examples of ESM concepts of operations and potential future ELINT threats that use techniques like LPI, frequency hopping, and spread spectrum.
This document provides an introduction and refresher on decibels (dB), which are commonly used to measure power levels, voltages, noise figures, and other quantities. It explains the definition of dB, what dBm means, and the difference between voltage dB and power dB. The document also covers how to convert between dB and percentage values and how to perform calculations when adding or comparing dB quantities. It aims to help engineers better understand and apply the dB scale in their work.
Radar 2009 a 19 electronic counter measuresForward2025
This document contains slides from a lecture on electronic countermeasures (ECM) against radar systems. It discusses how ECM techniques like chaff, noise jamming and random pulses can be used to mask targets from radar detection by increasing clutter. It provides details on how chaff works, including its reflectivity properties and how it is dispensed. Examples are given of chaff masking an aircraft and deceiving trackers. The presentation also introduces how electronic counter-countermeasures (ECCM) can be used to counter ECM techniques.
The document discusses different types of radar systems and their components and principles of operation. It covers topics like pulse radar vs continuous wave radar, components of each type of system like transmitter, receiver, antennas, and how factors like pulse width, repetition frequency and power affect radar performance and capabilities. It also discusses modulation techniques, antenna beam formation, and different types of radar displays.
This document discusses continuous wave (CW) radar and frequency modulated continuous wave (FMCW) radar. It defines radar as an electromagnetic device that can detect objects hidden from view using radio waves. Radar is classified into primary types including CW and modulated radar. CW radar uses the Doppler effect to detect moving targets based on changes in transmitted frequency. However, CW radar cannot determine range. FMCW radar modulates the transmitted frequency over time and compares the received frequency to determine both range and radial velocity of targets. Key applications of radar include military surveillance, weather monitoring, air traffic control and more.
Radar is a system that uses radio waves to detect objects by transmitting electromagnetic waves and analyzing the reflected signals. It consists of a transmitter that generates radio waves, a receiver to detect the reflected waves, and an antenna to transmit and receive the signals. Radar can determine attributes of detected objects such as range, angle, or velocity. It has numerous military and civilian applications including air traffic control, weather monitoring, vehicle speed detection, and space exploration. The Indian Army employs various radar systems like the Rohini, Rajendra, Indra, and Swordfish radars to detect threats. Radar remains an important detection technology due to its all-weather capabilities and ability to sense objects day or night through cloud cover.
This White Paper provides a general overview of various military and commercial radar systems. It also covers some typical measurements on such systems and their components.
Learn more about Radar Component Testing here: https://www.rohde-schwarz.com/solutions/test-and-measurement/aerospace-defense/radar-ew-test/radar-component-testing/radar-component-testing_250800.html
Radar uses radio waves to detect objects and determine their range, direction, and speed. It works by transmitting pulses of radio waves and receiving the echoes bounced back from objects. The time delay between transmission and reception is used to calculate distances to targets. Doppler radar uses the Doppler effect of radio waves to detect how fast targets are moving based on changes in frequency of the echoes.
This document provides an overview of radar cross section (RCS) and techniques for predicting a target's RCS through both measurement and theoretical calculation. It begins with definitions of RCS and factors affecting it. Examples of typical RCS values for different targets are given. Physical scattering mechanisms and contributors to a target's RCS are described. Both full-scale and scale model target measurement techniques are outlined. Theoretical prediction methods including geometrical optics, physical optics, and diffraction theories are introduced. Scaling laws for applying results from scale models to full-scale targets are also covered.
RADAR stands for Radio Detection and Ranging. It uses electromagnetic waves to detect objects like aircraft, ships, vehicles, weather formations and terrain by determining their range, altitude, direction or speed. The basic principles of radar involve transmitting pulses and measuring their time of return to determine characteristics of detected objects like distance, direction and elevation angle. Interference from noise, clutter and jamming can reduce radar detection capabilities.
Radar was originally developed for military purposes during World War 2 to detect ships and airplanes. Scientists later discovered that radar could also detect precipitation, making it an essential tool for weather prediction. There are two main types of radar: pulse radar which uses pulse transmission to determine range and continuous wave radar which relies on the Doppler effect. Key radar components include the transmitter, receiver, antenna, and display unit. Radar systems can be classified by their primary mission as search, tracking, or weather surveillance radars. Common examples include air search radars, long range surveillance radars, and tracking radars used in aircraft.
Radar 2009 a 12 clutter rejection basics and mtiForward2025
This document contains lecture slides about radar clutter rejection techniques. It discusses the history of moving target indication (MTI) and how digital technology has enabled more advanced processing. MTI uses Doppler filtering to suppress stationary clutter and detect moving targets. Early MTI employed crude subtraction of stored pulses. Modern digital implementations allow complex signal processing over many pulses for improved clutter cancellation.
RADAR stands for Radio Detection and Ranging. It uses radio waves to determine the range, altitude, direction or speed of objects. The document discusses the basic principles and components of radar systems. It describes how pulsed radar works by transmitting pulses and calculating distance based on time of flight. Continuous wave radar is also covered, which can determine velocity using Doppler shift. Applications discussed include navigation, weather monitoring, air traffic control and military uses such as early warning systems and missile guidance.
RADAR stands for Radio Detection and Ranging. It uses electromagnetic waves to detect the position, velocity, and characteristics of targets. RADAR was originally developed for military purposes during World War 2, when it was used by the British and US militaries to locate ships and airplanes. Today, RADAR is an essential tool for weather prediction and analysis. Different types of RADAR include pulse transmission RADAR and continuous wave RADAR. RADAR comes in various forms such as search RADAR for detection and tracking RADAR for following individual targets. The frequency used depends on the desired range, with lower frequencies allowing longer detection distances.
Radar 2009 a 15 parameter estimation and tracking part 1Forward2025
The document discusses a lecture on parameter estimation and tracking in radar systems. It covers topics like observable estimation including range, angle, Doppler, and amplitude measurement accuracy. It also discusses single target tracking techniques such as amplitude monopulse, phase comparison monopulse, sequential lobing, and conical scanning. The outline indicates it will cover multiple target tracking and provide a summary. Diagrams are included to illustrate concepts like angular tracking error sources and Doppler estimation.
This document provides an overview of software-defined radio (SDR), including its definition, history, advantages, technical overview, and architecture. SDR is defined as a radio system where components typically implemented in hardware, such as mixers and filters, are instead implemented through software. The term was coined in 1991, with an early military project in 1992. SDR provides advantages like complete digital baseband processing and faster software prototyping. Its technical overview describes ideal SDR components and practical implementations using digital signal processing and field-programmable gate arrays.
WE3.L10.2: COMMUNICATION CODING OF PULSED RADAR SYSTEMSgrssieee
The document discusses using OFDM signals for both radar detection and communication. It proposes a system called "RadCom" that uses coded OFDM signals to achieve high data rates for communication payloads while also providing high processing gain for radar functions like range and velocity detection. Key advantages of OFDM signals for this joint system include robust modulation for communications, the ability to do Doppler processing, and potential for digital beamforming to improve angular resolution. Simulations and measurements demonstrate the feasibility of OFDM signals to achieve both radar imaging and binary data transfer with a single transmission.
Working Processes Of Radar
History – Before Radar
Principle Of Operation
Radio Detection And Ranging
Radar Functions
Radar Bands And Usage
Terminology Of Radar Systems
Radar Range Equation
Types Of Radar
Pulse RADAR
Duplexer Using Pin Switches
Doppler Effect
Principle Of Continuous Wave Radar
Principles Of MTI RADAR
Different Types Of RADAR & It’s Applications
This document provides an overview of key concepts in radio frequency (RF) technology for wireless communication systems. It defines terms like dBm for measuring power, and modulation schemes like amplitude shift keying (ASK), frequency shift keying (FSK), and phase shift keying (PSK) for encoding digital signals onto radio carriers. The document also outlines considerations for selecting an appropriate low-power wireless solution, including radio spectrum and network types.
Radar 2009 a 16 parameter estimation and tracking part2Forward2025
This document summarizes a lecture on parameter estimation and tracking. It discusses tracking processes like track association, initiation, maintenance through prediction and updating, and termination. Filtering techniques like the Kalman filter are presented as ways to estimate target position and velocity while accounting for noise and maneuvers. Examples of civilian and military target maneuvers are provided to illustrate the challenges of tracking.
This document provides an introduction to electronic warfare analyses. It discusses definitions of ELINT and EW terminology. It also covers topics like ELINT collection cycles, RF receiver characteristics, direction finding analysis, scan pattern analysis, and PRI analysis. The document puts these concepts together using examples of ESM concepts of operations and potential future ELINT threats that use techniques like LPI, frequency hopping, and spread spectrum.
This document provides an introduction and refresher on decibels (dB), which are commonly used to measure power levels, voltages, noise figures, and other quantities. It explains the definition of dB, what dBm means, and the difference between voltage dB and power dB. The document also covers how to convert between dB and percentage values and how to perform calculations when adding or comparing dB quantities. It aims to help engineers better understand and apply the dB scale in their work.
This document discusses electronic warfare and is divided into three main sections: electronic attack, electronic protection, and electronic warfare support. Electronic attack involves jamming, deception, and destructive techniques to interfere with an enemy's use of the electromagnetic spectrum. Electronic protection techniques are used to protect friendly forces from electronic attack. Electronic warfare support passively detects and analyzes emissions to gather intelligence and provide situational awareness. Specific electronic warfare systems and techniques discussed include jamming, chaff, flares, anti-radiation missiles, frequency hopping, and ELINT/COMINT collection.
This white paper provides a brief technology introduction on the 802.11ac amendment to the successful 802.11- 2007 standard. 802.11ac provides mechanisms to increase throughput and user experience of existing WLAN and will build on 802.11n-2009.
For more information on wireless connectivity test solutions, visit http://wireless-connectivity-test.com
As with all electronic test equipment, digital oscilloscopes have an array of key specifications. Some are basic and easy to understand. Other specifications (which may have a greater impact on the accuracy of your measurements) are not as clear and are often dependent on the manufacturer.
This primer gives insight into the most important specifications to consider when using an oscilloscope — beyond the banner specs.
Main topics include:
- Types of digital oscilloscopes
- Basic elements of digital oscilloscopes
- The display system and user interface
- Probes
- Oscilloscope benchmark specifications
- Typical oscilloscope measurements
For more information on digital oscilloscopes, visit http://rohde-schwarz-scopes.com
Access the video from this presentation for free from
http://www.rohde-schwarz-usa.com/DebuggingEMISS_On-Demand.html
Overview:
Electromagnetic interference is increasingly becoming a problem in complex systems that must interoperate in both digital and RF domains. When failures due to EMI occur it is often difficult to track down the sources of such failures using standard test receivers and spectrum analyzers. The unique ability of real-time spectrum analysis and synchronous time domain signal acquisition to capture transient events can quickly reveals details about the sources of EMI.
What You Will Learn:
How to isolate and analyze sources of EMI using an oscilloscope
Measurement considerations for correlating time and frequency domains
Near field probing basics
Presented By:
Dave Rishavy, Product Manager Oscilloscopes, Rohde & Schwarz
Dave Rishavy has a BS in Electrical Engineering from Florida State University and an MBA from the University of Colorado. Prior to joining Rohde and Schwarz, Mr. Rishavy gained over 15 years of experience in the test and measurement field at Agilent Technologies. This included positions in a wide range of technical marketing areas such as application engineering, product marketing, marketing management and strategic product planning. While at Agilent, Dave led the marketing and industry segment teams for the Infiniium line of oscilloscopes as well as high end logic analysis.
Switched mode power supplies have become ubiquitous in electronics as they provide precise voltages including high power with very high efficiency. The efficiency of these power supplies requires low loss power transistors and the design requires measurement of highly dynamic voltages. Voltage levels can vary from millivolts to hundreds of volts in some applications. In this seminar, the proper use of a digital oscilloscope to accurately measure these voltages will be discussed along with key aspects of instrument performance such as noise and overdrive recovery that affect the accuracy of the measurement.
(Slides from Live webinar on September 25, 2014, presented by Mike Schnecker. Watch the webinar On-Demand here: http://goo.gl/LkjUUg)
Attendees Will Learn:
An overview of switched mode power supplies
Common measurements (ie, what to measure and why)
Circuit loading and probing considerations
How instrument specifications impact measurement accuracy
Switched mode power supplies have become ubiquitous in electronics as they provide precise voltages including high power with very high efficiency. The efficiency of these power supplies requires low loss power transistors and the design requires measurement of highly dynamic voltages. Voltage levels can vary from millivolts to hundreds of volts in some applications.
In this webinar, the proper use of a digital oscilloscope to accurately measure these voltages will be discussed along with key aspects of instrument performance such as noise and overdrive recovery that affect the accuracy of the measurement.
The document is a magazine for the 9th Annual Military Radar Summit that includes:
- An introduction to cognitive radar and its potential as a fully autonomous system that can learn from mission to mission.
- An interview with experts discussing challenges with cognitive radar like lagging software development and regulatory clearance needs.
- An overview of the summit's agenda addressing topics like multi-input multi-output radar, low size weight and power AESAs for UAVs, and prioritizing radar initiatives.
- Details of the summit location, dates, and invitation from the chairman to attend the event focusing on advances in military radar.
The document discusses radar clutter from unwanted objects like ground, sea, rain, and birds/insects. It provides examples of military radars for which clutter is an issue and outlines factors that affect ground clutter backscatter like terrain type, frequency, and depression angle. Median ground clutter strength values are shown for various terrain types and frequencies.
Radar 2009 a 2 review of electromagnetism3Forward2025
The Institute of Electrical and Electronics Engineers (IEEE) is a professional association for electronic engineering and electrical engineering. Founded in 1963, IEEE has over 420,000 members in over 160 countries and publishes over 200 transactions, journals and magazines. IEEE sets standards for electric power, telecommunications, computer engineering, medical technology, biotechnology, and aerospace among other fields.
This document provides an overview and agenda for an oscilloscope fundamentals workshop. The agenda covers choosing an oscilloscope, probing basics including passive probe compensation and ground lead effects, vertical system components like input coupling and scale, sampling and acquisition concepts like aliasing and rate, horizontal system parameters, trigger systems including runt triggering, and using an oscilloscope for EMI debugging. Hands-on workshops are included to demonstrate various topics like probe compensation, ground loop effects, input coupling, aliasing, display update rate, and using near-field probes for EMI analysis. The goal is to review important oscilloscope concepts and allow participants to experiment with the effects of different settings and probe techniques.
Space Radiation & It's Effects On Space Systems & Astronauts Technical Traini...Jim Jenkins
This course is designed for technical and management personnel who wish to gain an understanding of the fundamentals and the effects of space radiation on space systems and astronauts. The radiation environment imposes strict design requirements on many space systems and is the primary limitation to human exploration outside of the Earth's magnetosphere. The course specifically addresses issues of relevance and concern for participants who expect to plan, design, build, integrate, test, launch, operate or manage spacecraft and spacecraft subsystems for robotic or crewed missions. The primary goal is to assist attendees in attainment of their professional potential by providing them with a basic understanding of the interaction of radiation with non-biological and biological materials, the radiation environment, and the tools available to simulate and evaluate the effects of radiation on materials, circuits, and humans
Embedded systems increasingly employ digital, analog and RF signals all of which are tightly synchronized in time. Debugging these systems is challenging in that one needs to measure a number of different signals in one or more domains (time, digital, frequency) and with tight time synchronization. This session will discuss how a digital oscilloscope can be used to effectively debug these systems, and some of the instrumentation considerations that go along with this.
ELINT Interception and Analysis course samplerJim Jenkins
The course covers methods to intercept radar and other non-communication signals and a then how to analyze the signals to determine their functions and capabilities. Practical exercises illustrate the principles involved.
Radar 2009 a 6 detection of signals in noiseForward2025
This document summarizes a lecture on radar signal detection. It discusses detecting signals in noise, the radar detection problem, basic target detection tests, and how detection performance is affected by factors like signal-to-noise ratio and number of integrated pulses. It outlines concepts like probability of detection, probability of false alarm, and the tradeoff between the two. Integration of multiple pulses can improve performance through coherent or non-coherent integration. Fluctuating targets are also addressed.
This document provides an overview of a course on radar systems engineering to be presented by Dr. Robert O'Donnell. The course was initially developed in 2000 for engineers and scientists with little radar experience. It covers core topics in radar fundamentals and subsystems over multiple lectures. The course has evolved significantly and now includes additional material on radar applications. It is intended to provide students a broad understanding of radar principles and issues. Copyrighted material from MIT Lincoln Laboratory and industry will be used with permission.
This document contains lecture slides about radar signal propagation through the atmosphere. It discusses various propagation effects including reflection from the Earth's surface, atmospheric refraction, multipath interference, and attenuation. It provides equations for calculating propagation losses and phase differences between direct and reflected signals. Examples are given of how propagation affects radar coverage and detection range for a shipborne surveillance radar system.
This document contains 20 slides from a lecture on radar systems and the radar equation. The slides cover topics such as the basic components of a radar system, definitions of terms like radar cross section, development of the radar range equation, sources of noise, and examples of how radar performance scales with different design parameters. Key aspects of the radar equation like transmitter power, antenna size, range, losses, and noise temperature are discussed across the slides.
Jitter measurements are commonly done taking small snapshots in time, yet systems often experience jitter from sources that occur over relatively long time intervals, which may not be accounted for using short time interval measurements methods.
In this webinar we will present the application of a real time, digital clock recovery and trigger system to the measurement of jitter on clock and data signals. Details of the measurement methodology will be provided along with measurement examples on both clock and data signals.
You Will Learn:
- What is Jitter
- Different types of Jitter
- Jitter measurement techniques
- Benefits of Jitter analysis using real-time DDC techniques
The document discusses adaptive moving target indication (MTI) radar. It describes how MTI radar uses the Doppler effect to discriminate moving targets from stationary clutter. Adaptive filters can be used for MTI to adjust to spatially and temporally varying clutter environments. The objective of the project is to design an adaptive MTI filter with improved performance in non-stationary clutter environments. This will involve estimating pulse-to-pulse amplitude variations of the clutter process and implementing this estimator in the adaptive MTI filter to help it adapt to non-stationary clutter behavior. Results applying this adaptive MTI filter to real radar data show extensive reduction in clutter detections in the radar image.
This document provides an overview of synthetic aperture radar (SAR) and pulse compression techniques. It discusses how pulse compression allows radar systems to achieve fine range resolution while transmitting long duration, lower power pulses. This compromises between range resolution, signal strength, and transmitter power requirements. Pulse compression techniques like chirp modulation and stretch processing are described. The document also covers topics like range and azimuth resolution, geometric distortions, and signal processing methods used in SAR systems.
The document discusses MTI (Moving Target Indication) and pulse Doppler radars. It explains that MTI radars use techniques like delay line cancellation to eliminate echoes from stationary clutter and detect moving targets. Pulse Doppler radars employ the Doppler shift caused by target motion to detect targets. Key differences are noted - MTI radars have no range ambiguities but Doppler ambiguities, while pulse Doppler radars have the opposite problem. Blind speeds, limitations of CW radar, and techniques to overcome issues like flicker noise and lack of isolation are also covered. Applications of CW radar like speed measurement are mentioned.
This document discusses MTI (Moving Target Indication) and pulse Doppler radars. It begins by explaining how clutter like land, sea, and weather can interfere with radar detection of targets. It then describes the Doppler effect which causes a shift in frequency when the radar or target is in motion, allowing CW radars to detect moving targets. MTI radars use a technique called pulse cancellation to remove stationary clutter and detect moving targets. Pulse Doppler radars also use Doppler shift but have a high pulse repetition frequency which avoids ambiguities. The document discusses limitations of CW and MTI radars and techniques to overcome them like using multiple frequencies or pulse repetition frequencies. It includes diagrams of radar systems and equations for Doppler shift.
This document provides an overview of the course content for Unit 1 of a radar systems course. It covers basics of radar including introduction, maximum unambiguous range, simple radar range equation, radar block diagram and operation, radar frequencies and applications, prediction of range performance, minimum detectable signal, and receiver noise. Examples of topics covered include derivation of the fundamental radar range equation, description of typical radar transmitter and receiver components, and applications of radar systems for air, sea, and space.
This document outlines a unit plan on radar communication. It includes sections on radar principles and applications, radar frequency bands, pulse-related terms, the radar range equation, duplexer and display systems, types of radar including pulse, CW, FMCW, MTI and secondary radar, landing systems including ILS and GCA, and an introduction to SONAR. Various radar concepts are defined and block diagrams of radar systems are provided with explanations. The unit plan allocates 1 hour for each sub-section and includes learning objectives.
Radar is a detection system that uses radio waves to determine the range, ang...vijay525469
Radar is a detection system that uses radio waves to determine the range,
angle, or velocity of objects. It can be used to
detect aircraft, ships, spacecraft, guided missiles,motor vehicles, weather
formations, and terrain.
International Journal of Computational Engineering Research(IJCER)ijceronline
The document describes an active cancellation algorithm for radar cross section reduction. The algorithm uses hardware components like receiving and transmitting antennas along with software like MATLAB and C programs. It works by receiving an incoming radar signal, analyzing its parameters, searching databases to find matching echo data, generating a cancellation signal to transmit, and establishing scattering fields to synthesize an empty pattern for the radar receiver. Testing showed the algorithm improved visibility reduction by 25% over conventional methods.
Subsystems of radar and signal processing Ronak Vyas
This document discusses subsystems of radar and signal processing, specifically focusing on ST (Stratosphere Troposphere) radar. It begins by introducing the goals of understanding basic radar concepts and studying ST radar. It then provides an overview of key radar subsystems including antennas, duplexers, transmitters, and receivers. The document concludes by describing common signal processing techniques used in radar like correlation, Doppler filtering, and detection processing.
Radar was invented in the early 1900s and applied during World War II to detect aircraft. The basic principles of radar involve transmitting electromagnetic signals that are reflected off targets and detected. A typical radar system includes a transmitter, antenna, receiver, and display. The radar range equation relates key variables such as transmitted power, wavelength, target radar cross-section, and system losses to the maximum detectable range. Integration of multiple radar returns can improve the signal-to-noise ratio and increase detection range.
Radar was invented in the early 1900s and applied during World War II to detect aircraft. The basic principles of radar involve transmitting electromagnetic signals that are reflected off targets and detected. A typical radar system includes a transmitter, antenna, receiver, and display. The radar range equation relates key variables such as transmitted power, antenna gain, target radar cross-section, and noise power to determine maximum detection range.
Pulse Compression Method for Radar Signal ProcessingEditor IJCATR
One fundamental issue in designing a good radar system is it’s capability to resolve two small targets that are located at
long range with very small separation between them. Pulse compression techniques are used in radar systems to avail the benefits
of large range detection capability of long duration pulse and high range resolution capability of short duration pulse. In these
techniques a long duration pulse is used which is frequency modulated before transmission and the received signal is passed through a
match filter to accumulate the energy into a short pulse. A matched filter is used for pulse compression to achieve high signal-to-noise
ratio (SNR). Two important factors to be considered for radar waveform design are range resolution and maximum range detection.
Range resolution is the ability of the radar to separate closely spaced targets and it is related to the pulse width of the waveform. The
narrower the pulse width the better is the range resolution. But, if the pulse width is decreased, the amount of energy in the pulse is
decreased and hence maximum range detection gets reduced. To overcome this problem pulse compression techniques are used in the
radar systems. In this paper, the pulse compression technique is described to resolve two small targets that are located at long
range with very small separation between them.
This document provides an overview of radar basics and concepts. It discusses that radar uses radio waves to detect and locate objects called targets. The key components of a radar system include a transmitter, receiver, and antennas. There are different types of radars based on antenna locations and transmitted waveforms. Radars can perform functions like detection, measurement of range, velocity, and angle. Factors like waveform, power, frequency, and resolution impact radar performance. Continuous wave and pulsed radars are described. Doppler frequency shifting is used to determine target velocity.
This document discusses radar echo signals and multipath fading. It begins with an abstract that introduces multipath propagation as a phenomenon where radar signals take multiple paths upon reflection, in addition to the direct line of sight path. This can cause interference and fading effects. The document then provides background on radar systems and the radar range equation. It presents an approach to process received radar signals to isolate the main line of sight echo and discard weaker multipath signals. This involves analyzing signal amplitudes and retaining the highest value signal. The system components for implementing this approach include a fast microcontroller, computer, and lab link cable for programming the microcontroller using BASIC language software.
The document discusses Moving Target Indicator (MTI) radar. MTI radar uses Doppler shift to distinguish between stationary clutter and moving targets. It eliminates clutter by processing return signals coherently and comparing successive pulses to detect amplitude variations from moving targets. MTI radar is implemented using delay line cancellers, transversal filters, or multiple pulse repetition frequencies to filter out clutter returns while passing signals from moving targets.
1. Radar cross section (RCS) is a measure of how much electromagnetic energy is reflected back towards the radar from a target and is compared to that reflected from a smooth sphere of cross-sectional area 1 m^2. RCS depends on the target's physical geometry, composition, and orientation with respect to the radar.
2. For a sphere, RCS is equal to the sphere's physical cross-sectional area and is independent of frequency in the optical region where the wavelength is much smaller than the sphere's radius. In other regions, RCS can vary with frequency due to interference between specularly reflected waves and creeping waves that follow the sphere's surface.
3. Reducing the RCS of
1) The document discusses parameters used to characterize mobile multipath channels including power delay profile, mean excess delay, RMS delay spread, maximum excess delay, coherence bandwidth, Doppler spread, and coherence time.
2) These parameters are derived from the power delay profile and describe aspects of the channel such as time dispersion, frequency selectivity, and time variation due to Doppler shift.
3) Examples of typical values for different channel parameters are given for outdoor and indoor mobile radio channels.
A small vessel detection using a co-located multi-frequency FMCW MIMO radar IJECEIAES
Small vessels detection is a known issue due to its low radar cross section (RCS). An existing shore-based vessel tracking radar is for long-distance commercial vessels detection. Meanwhile, a vessel-mounted radar system known for its reliability has a limitation due to its single radar coverage. The paper presented a co-located frequency modulated continuous waveform (FMCW) maritime radar for small vessel detection utilising a multiple-input multiple-output (MIMO) configuration. The radar behaviour is numerically simulated for detecting a Swerling 1 target which resembles small maritime’s vessels. The simulated MIMO configuration comprised two transmitting and receiving nodes. The proposal is to utilize a multi-frequency FMCW MIMO configuration in a maritime environment by applying the spectrum averaging (SA) to fuse MIMO received signals for range and velocity estimation. The analysis was summarised and displayed in terms of estimation error performance, probability of error and average error. The simulation outcomes an improvement of 2.2 dB for a static target, and 0.1 dB for a moving target, in resulting the 20% probability of range error with the MIMO setup. A moving vessel's effect was observed to degrade the range error estimation performance between 0.6 to 2.7 dB. Meanwhile, the proposed method was proven to improve the 20% probability of velocity error by 1.75 dB. The impact of multi-frequency MIMO was also observed to produce better average error performance.
4g LTE and LTE-A for mobile broadband-notePei-Che Chang
This document discusses the basic principles of OFDM (Orthogonal Frequency Division Multiplexing) transmission. It covers several key topics:
1) OFDM uses multiple subcarriers to transmit data in parallel. The subcarriers are spaced closely together with minimal spacing between them.
2) OFDM modulation and demodulation can be implemented efficiently using IDFT/DFT (IFFT/FFT) processing.
3) Cyclic prefixes are added to combat inter-symbol interference from multipath channels. This preserves subcarrier orthogonality.
4) With a cyclic prefix, the channel appears flat on each subcarrier, allowing one-tap frequency domain equalization. Channel estimation is done using reference symbols.
Introduction to Radar, Radar classification, The simple form of the Radar equation, Radar block diagram and operation, The Doppler Effect, Simple CW Radar Block Diagram, Block diagram of CW doppler radar with nonzero IF receiver, Applications of CW radar, Block Diagram of Frequency Modulated CW Radar
radar range equation
Similar to Dr. Wiley - PRI Analysis and Deinterleaving (20)
Much of the success or failure of #5G will come down to securing the right amount of spectrum, at the right cost, under the right conditions. Here's where specific regions are placing their bets.
*As of April 26, 2019.
Learn more about 5G solutions from Rohde & Schwarz:
http://bit.ly/2ILV7cA
Technology Manager Andreas Roessler covers 5G basics in this keynote presentation at the RF Lumination 2019 conference in February 2019.
RF Lumination 2019
"Meet 158+ years of RF design & test expertise at one event. If they can't answer your question, it must be a really good question!"
Watch all the presentations here:
https://www.rohde-schwarz-usa.com/RFLuminationContent.html
Andreas Roessler is the Rohde & Schwarz Technology Manager focused on UMTS Long Term Evolution (LTE) and LTE-Advanced. With responsibility for the strategic marketing and product portfolio development for LTE/LTE-Advanced, Andreas follows the standardization process in 3GPP very closely, particularly on core specifications as well as protocol conformance, RRM and RF conformance specifications for device and base stations testing. He graduated from Otto-von-Guericke University in Magdeburg, Germany, and received a Master's Degree in communication engineering.
This document provides an introduction to RF design, covering key concepts such as the RF spectrum, transmitter and receiver components like antennas, filters, amplifiers and mixers, and modulation techniques. It also discusses important considerations for RF link design such as link budget and environmental factors. Test equipment used for verification is explained, including spectrum analyzers, signal generators, vector network analyzers and power meters. The goal is to provide foundational knowledge for the design of radio frequency systems.
The document provides an introduction to vector network analysis. It discusses key topics like transmission lines, S-parameters, network analyzer architecture, calibration techniques, and common measurements. Vector network analyzers are used to characterize two-port devices by measuring the amplitude and phase of signals transmitted and reflected within the device. Calibration is necessary to remove systematic measurement errors and allow accurate determination of S-parameters.
This document discusses crosstalk measurements for signal integrity applications. It begins with an introduction to crosstalk, including a brief history, definition, why it is important, and types of crosstalk. It then covers measurement methods for crosstalk, including time domain and frequency domain measurements. Frequency domain measurements using a vector network analyzer are highlighted as they provide accurate, high dynamic range characterization of crosstalk. The document stresses the importance of crosstalk characterization given increasing data rates and device densities.
This document discusses measuring jitter using phase noise techniques. It begins with an overview of jitter and phase noise concepts. It then describes how jitter can be measured in the time domain using an oscilloscope and in the frequency domain using a phase noise analyzer. It explains how phase noise measurements can be used to derive random and deterministic jitter. The document provides examples of measuring very low jitter signals and calculating jitter contributions from phase noise spurs. It concludes with a discussion of calculating peak-to-peak jitter from RMS jitter measurements and references for further information.
The document provides an overview of advanced spectrum analyzer measurements and architecture. It begins with a definition of a spectrum analyzer and its basic components. It then discusses features such as resolution bandwidth, detectors, and measurements over time. The document outlines the evolution of spectrum analyzer capabilities from the 1990s to present. It concludes with descriptions of standard measurements and an introduction to advanced measurements capabilities of modern spectrum analyzers.
Differential structures such as backplanes and cables are the primary means for transmitting high speed serial data signals. Signal integrity of these systems is determined by the characteristics of the media such as insertion loss, crosstalk, and differential to common mode conversion.
Complete measurement of the mixed mode s-parameters is often performed by transforming single-ended s-parameters and assuming that the system is linear. In some cases, linearity cannot be assumed such as where active components are used.
This presentation describes how to measure true differential s-parameters which can be measured even in the presence of non-linear elements.
The USB 2.0 standard is widely deployed in both computer and embedded systems. Compliance testing for this standard includes signal integrity as well as a number of low-level protocol tests.
This presentation provides an overview of the test requirements for USB 2.0 compliance and provide background on each test case. Details of fixtures and signal integrity requirements are highlighted in detail.
For more information visit http://rohde-schwarz-scopes.com or call (888) 837-8772 to speak to a local Rohde & Schwarz expert.
Originally presented at DesignCon 2013.
Jitter is a very important topic in signal integrity for high speed serial data links. The jitter performance of clock signals used in generating the serial data signal is critical to the overall performance of these signals.
Phase noise is the most sensitive and accurate measurement of the performance of precision clocks.
This presentation covers the theory and practice for making phase noise measurements on clock signals as well as the relationship between phase noise and total jitter, random jitter and deterministic jitter. Measurements on a typical clock signal is also included.
For more information, visit http://rohde-schwarz-scopes.com or call (888) 837-8772 to speak to a local Rohde & Schwarz expert.
This seminar will provide the basics of this fascinating technology. After attending this seminar you will understand OFDM-principles,
including SC-FDMA as the transmission scheme of choice for the LTE uplink. Multiple antenna technology (MIMO) is a fundamental
part of LTE and its impact on the design of device and network architecture will be explained. Further LTE-related physical layer
aspects such as channel structure and cell search will be presented with an overview of the LTE protocol structure.
The second part of the seminar provides an overview of the evolution in LTE towards 3GPP specification Release 9 and 10. This
includes features and methods for location based services like GNSS support or time delay measurements and the concept of
multimedia broadcast. Finally, we’ll introduce the main features of LTE-Advanced (3GPP Release-10) including carrier aggregation for
a larger bandwidth and backbone network aspects like self-organizing networks and relaying concepts.
UMTS Long Term Evolution, LTE, is the technology of choice for the majority of network operators worldwide for providing mobile
broadband data and high-speed internet access to their subscriber base. Due to the high commitment LTE is the innovation platform
for the wireless industry for the next decade.
This class will provide the basics of this fascinating technology. After attending this course you will have an understanding of
OFDM-principles including SC-FDMA as the transmission scheme of choice for the LTE uplink. Multiple antenna technology (MIMO),
a fundamental part of LTE, will be explained as well as its impact on the design of device and network architecture. We’ll give a quick
introduction into the evolution of this technology including future upgrades of LTE features like multimedia broadcast, location based
services and increasing bandwidth through carrier aggregation.
The second part of the course will provide an overview including practical examples and exercises on how to test a LTE-capable device
while performing standardized RF measurements such as power, signal quality, spectrum and receiver sensitivity. We’ll address how
to automate these measurements in a simple and cost-effective way. We will introduce application based testing by demonstrating
end-to-end (E2E), throughput and application testing using the Rohde & Schwarz R&S®CMW500 Wideband Radio Communication
Tester. Examples of application tests are voice over LTE, VoLTE or Video over LTE.
LTE Measurement: How to test a device
This course provides an overview with practical examples and exercises on how to test a LTE-capable device while performing standardized RF measurements such as power, signal quality, spectrum and receier sensitivity, and how to automate these measurements in a simple and cost-effective way. We will present testing of LTE handsets in terms of protocol signaling scenarios and handover to other radio technologies for interoperability. This course will demonstrate end-to-end (E2E), throughput and application testing using the Rohde & Schwarz R&S®CMW500 Wideband Radio Communication Tester. Examles of application tests are voice over LTE, (VoLTE) or Video over LTE.
Overview:
Embedded systems increasingly employ a combination of low speed serial, analog voltages and RF communications which are tightly synchronized in time. This session will discuss the background of performing time and frequency domain analysis on these systems with example measurements on a digitally controlled RF transmitter.
What will you learn?
The challenges of debugging embedded systems
Frequency domain analysis and FFT basics
Time gating, Dynamic range and Triggering considerations
PLL locking measurement example
Join us for a LIVE WEBINAR on this topic! Wednesday, November 14, 2:00pm ET
http://bit.ly/XPgjO7
Wide bandwidth modulation is becoming more common in communications. The emergence of the 802.11ac wireless Ethernet standard has extended the modulation bandwidth to 160 MHz which requires very wide band measurement equipment to measure. This presentation illustrates the details of a measurement method that uses a real time digital down converter and post processing software that measures the performance of this signal.
Near Field Communications (NFC) is an evolution of contactless data exchange which is being employed in mobile phone applications for data exchange and payment processing, among other applications. This presentation covers the evolution and technical details of this communications protocol along with compliance testing requirements.
Learn more: http://wireless-connectivity-test.com
5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
A Comprehensive Guide to DeFi Development Services in 2024Intelisync
DeFi represents a paradigm shift in the financial industry. Instead of relying on traditional, centralized institutions like banks, DeFi leverages blockchain technology to create a decentralized network of financial services. This means that financial transactions can occur directly between parties, without intermediaries, using smart contracts on platforms like Ethereum.
In 2024, we are witnessing an explosion of new DeFi projects and protocols, each pushing the boundaries of what’s possible in finance.
In summary, DeFi in 2024 is not just a trend; it’s a revolution that democratizes finance, enhances security and transparency, and fosters continuous innovation. As we proceed through this presentation, we'll explore the various components and services of DeFi in detail, shedding light on how they are transforming the financial landscape.
At Intelisync, we specialize in providing comprehensive DeFi development services tailored to meet the unique needs of our clients. From smart contract development to dApp creation and security audits, we ensure that your DeFi project is built with innovation, security, and scalability in mind. Trust Intelisync to guide you through the intricate landscape of decentralized finance and unlock the full potential of blockchain technology.
Ready to take your DeFi project to the next level? Partner with Intelisync for expert DeFi development services today!
Ocean lotus Threat actors project by John Sitima 2024 (1).pptxSitimaJohn
Ocean Lotus cyber threat actors represent a sophisticated, persistent, and politically motivated group that poses a significant risk to organizations and individuals in the Southeast Asian region. Their continuous evolution and adaptability underscore the need for robust cybersecurity measures and international cooperation to identify and mitigate the threats posed by such advanced persistent threat groups.
leewayhertz.com-AI in predictive maintenance Use cases technologies benefits ...alexjohnson7307
Predictive maintenance is a proactive approach that anticipates equipment failures before they happen. At the forefront of this innovative strategy is Artificial Intelligence (AI), which brings unprecedented precision and efficiency. AI in predictive maintenance is transforming industries by reducing downtime, minimizing costs, and enhancing productivity.
Trusted Execution Environment for Decentralized Process MiningLucaBarbaro3
Presentation of the paper "Trusted Execution Environment for Decentralized Process Mining" given during the CAiSE 2024 Conference in Cyprus on June 7, 2024.
Programming Foundation Models with DSPy - Meetup SlidesZilliz
Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Fueling AI with Great Data with Airbyte WebinarZilliz
This talk will focus on how to collect data from a variety of sources, leveraging this data for RAG and other GenAI use cases, and finally charting your course to productionalization.
1. PRI Analysis and Deinterleaving
Richard G. Wiley, Ph.D.
Research Associates of Syracuse, Inc
111 Dart Circle
Rome, NY 13441
315-685-3135; dwiley@ras.com
1
Pulse Repetition Intervals (PRIs) are often the key to
identifying the signals of many radar systems. The first step is
to deinterleave signals from multiple radar systems. This
briefing is a a brief introduction to PRI analysis and
deinterleaving from the ELINT/EW point of view
2
2. PULSE REPETITION INTEVAL (PRI)
3
ELINT Implications of Range Equations and Radar Constraints
The effects of the one-way range equation of ELINT and the twoway range equation of radar on signal strength must be understood
and explored in order to appreciate the typical situations
encountered in ELINT and EW. Similarly, the constraints placed on
radar waveforms must be understood in order to correctly interpret
the functions and applications of the signals transmitted by radar
and also to be aware of the signal characteristics expected to be
encountered by ELINT. In many ways, understanding these aspects
of ELINT is what separates one who only observes signals from one
who both observes and analyzes signals.
Reference: ELINT, Chapter 2
4
3. Radar and ELINT Range Equations
2
SR
PT GT G R
3
4
(4 ) R R LT LR
PT GTE G E 2
2
2
(4 ) R E LT LE
SE
5
Ratio of ELINT Range to Radar Range
A significant aspect of these range equations is that the power
level transmitted by pulsed radar transmitters in order to detect
targets at long range is very high. This allows ELINT receivers to
detect radar signal at very long ranges even when observing the
sidelobes of the radar’s transmit antenna.
To simplify the discussion, suppose that the ELINT receiver
requires a signal level that is a factor times the signal level
needed by the radar receiver, that is:
SE
RE
RR
RR
4
1 GTE G E LE
GT G R LR
6
(S R )
1/ 2
4. 3
1 10
RR
4
GR
100
Ma
RangeRatioSL
i
:
am
be
in
1/ 2
GT
=3
E
RE/RR
ELINT Range/Radar Range
RE
RR
RE
RR
B
0d
RangeRatioMBi
be
elo
Sid
10
: GT
=0
E
RR 4
GR
1/ 2
dB
A
1 sq. m
G
R
30 dB
100
G
E
1
1
10
100
1
Ri
Range (km)
Figure 2-1 ELINT to Radar Range Ratio
7
2.2 Radar Constraints
ELINT signals of interest include radar signals of all types.
Sometimes, people concerned about ELINT attribute properties
to radar signals that are contrary to the constraints under which
radar systems must function. Avoiding this pitfall is an
important aspect of ELINT work. Understanding the
fundamental limitations faced by radar designers and the
associated ELINT implications is important. Consider this
statement: “Radars of the future could transmit noise
waveforms over GHz bandwidths and be undetectable by
ELINT receivers.” Should ELINT equipment be developed to
intercept and process this kind of signal? Probably not-because signals like this would not be useful for tracking or
search radars in military applications.
8
3
1 10
5. Range Resolution related to Bandwidth
Range resolution in radar is inversely proportional to the
bandwidth of the signal (assuming that it is processed
coherently). The fundamental relationship is:
c
R
2B
Here c is the speed of light and B is the bandwidth of the signal
during the coherent processing interval; also called its
instantaneous bandwidth.
For example, to distinguish between two fighters in tight
formation 30m apart in range, BW must be about 5MHz. If one
postulates a value of B=1 GHz, the radar has a range resolution
of 15 cm. This means that the target echoes are resolvable in
15 cm range increments called range cells. The echoes from a
75m target are spread across 500 range cells.
9
Range Resolution (meters)
Range Resolution (meters)
1 10
3
100
RngRes bi
10
1
6
1 10
7
1 10
bi
Bandwidth (MHz)
Bandwidth B (MHz)
1 10
8
Figure 2.2. Range resolution Related to Radar Coherent Bandwidth
10
6. This spreading of the echoes across a multiplicity of range cells reduces the apparent radar
cross-section (and thus reduces the SNR available) in a single range cell. For this reason,
radar designs generally have range resolution appropriate for their function. This leads to
choosing coherent bandwidths of 10 MHz or less. (10 MHz corresponds to range
resolution of 15 m.) In this sense, there is no such thing as a “spread spectrum” radar—
what is transmitted is also received and the resulting range resolution is determined by the
bandwidth. What this means for ELINT is that the coherent bandwidth of radar signals is
likely to remain the same as it is now provided the radar performs the same task.
Range Resolution Required
Resolution (m)
Bandwidth (MHz)
30
60
5
2.5
2. Detect missile
separation at launch
15
10
3. Imaging of Ships,
Vehicles and Aircraft
.5-1
150-300
4. High Resolution
Mapping
0.15
1000
1.Count A/C in attack
formation
11
Moving Targets and Integration Time Constraints
If a radar is to detect targets moving in a radial direction (toward or
away from the radar), the amount of time the target will be present in a
given range cell is determined by the target velocity and the range
resolution. This limits the coherent integration time of present day
radars to
R
R
TCV
v
v
Here TCV is the maximum coherent integration time for a constant
velocity target with radial velocity v and R is the change in range
during that time. If the target is accelerating in the radial direction,
the maximum integration time is now a quadratic function of both
velocity and acceleration
T ACC
v
v
2
2a ( R )
a
12
0.5
v
v
2
2a ( R )
a
0.5
7. Constraints on Time-Bandwidth Product or Pulse Compression
Ratio
Because range resolution is determined by bandwidth and integration
time is determined by velocity, there is a natural limit on the product
of the instantaneous bandwidth and the duration of the coherent
processing interval or pulse width. This is called the "timebandwidth product." The radar's pulse compression ratio is limited to
no more than its time bandwidth product. By combining Equations
for range resolution and integration time it is easy to see that the time
bandwidth product is limited to:
Bv
a
BT
ac
1
Bv 2
1
a
0
c
2v
13
BT Limit
Maximum time-bandwidth product BT
1 10
6
a=0 g
BT i 1
BT i 2
a=1 g
BT i 5
g
a=2
BT i 10
a=5
g
BT1 i
10
a=
g
Acceleration 0, 1,2, 5, 10 g's
Velocity=300m/s
1 10
5
4
1 10
5
1 10
bi
Signal Bandwidth B (Hz)
Bandwidth
Figure 2-414
Limit on Time x Bandwidth
6
1 10
8. Constraints on Doppler Resolution
If the radar coherently integrates the echoes in one range cell for the
entire integration time, the minimum doppler filter bandwidth, Bf, is
approximately the reciprocal of the integration time,.T, which is
either TCV for constant velocity targets or TACC for accelerating
targets:.
1
T
Bf
However if the target is accelerating, the doppler shift changes.
Clearly there is a relationship between acceleration and the time the
doppler shift of the moving target remains within the doppler filter
bandwidth.
f acc
2aTf o
c
2aT
Bf
15
Because the coherent integration time is approximately equal
to 1/Bf, substituting Bf=1/T into 2-12 gives the maximum
allowable coherent integration time and the minimum doppler
filter bandwidth as
T
2a
, Bf
16
2a
9. 1 10
6.502 10
3
1 10
Doppler Spread( kHz)
4
a=10g
3
fi 1
100
fi 2
a=1g
fi 5
10
f i 10
1
0.65
0.1 3
1 10
1 10
0.01
0.1
3
1
Ti
1
Coherent Integration time T (s)
Figure 2.5 Doppler Spread and Maximum Signal Bandwidth
17
1 10
3
1000
1 10
Doppler Spread( kHz)
1 10
3
ple
Dop
fi 1
fi 2
100
r
ad
Sp r e
fi 5
f i 10
- ri gh
le
t sca
Ma
xi m
um
10
a=10g
a=5g
a=2g g
a=1
Bi
Sig
n
1
al B
10
and
w
0.65
0.1 3
1 10
0.01
100
idt
h
-le
f
t sc
ale
1
0.1
.001
Ti
Coherent Integration time T (s)
Figure 2.5 Doppler Spread and Maximum Signal Bandwidth
18
1
1
1
Bandwidth (MHz)
6.502 10
4
3
10. The doppler filter bandwidth must be no wider than the spread of
doppler frequencies expected. Figure 2-5 also shows the
maximum radar signal bandwidth. For the case where acceleration
has a minimal effect on the integration time, the maximum
acceleration of the target can be expressed in terms of the radar
signal's bandwidth as
a max
v2
2B 2
c( RF )
19
Long integration times require small target acceleration. The
radar designer must choose a bandwidth that suits the range
resolution required and integration to suit the target motion
expected. Long integration time implies either slow targets with
little acceleration or else poor range resolution. High
acceleration targets require wider signal bandwidths. An
aircraft target approaching at 300m/s and maneuvering at 3 g’s
needs a radar signal bandwidth of at least 2.5 MHz at 10 GHz.
Radar signals exhibit relatively constant characteristics during
coherent integration--important to know for ELINT analysis.
Tracking radars extend the coherent integration time when target
velocity and acceleration are known. Examining all possible
target velocities and accelerations requires huge processor
throughput and is generally not practical today.
20
11. Frequency Agility
From one coherent processing interval to the next, the radar can
change its carrier frequency without changing its range resolution
properties. The agility band is limited by the radar designer’s
ability to obtain sufficient power and to maintain beam width and
pointing angle--typically about 10% of the center frequency. (For
example, a 1 GHz agility band centered at 10 GHz.) What this
means for ELINT is that narrowband receivers have a low
probability of intercepting the complete radar transmission. If it is
sufficient to intercept only portions of the radar transmission,
narrowband receivers can be slowly tuned across the radar band
and the entire agility band can still be determined if the signals is
present for enough time. The coherent processing interval
determines the Doppler resolution. When FA is used with doppler
processing, the frequency is changed on a pulse-burst to pulseburst basis, not a pulse-to-pulse basis.
21
PRI Agility
Modern multifunction radar systems make use of multiple pulse
repetition intervals (PRI) values during one look at the target. It is
a requirement of today’s pulse doppler radars that the PRI remain
constant during each coherent processing interval. For moving
target indicating (MTI) radar designs, there is usually a sequence
of PRI values that must be completed during one processing
interval. This repeated sequence is known as "stagger" and ELINT
analysts call the period of the stagger the stable sum. This is
because when consecutive PRIs are added, the sum is constant
when one adds together the PRIs which make up the stagger
period--regardless of which PRI is selected as the starting point for
the sum.
22
12. MTI radars operate by subtracting (in amplitude and phase) the
echoes from one PRI from those in the next PRI. Stationary targets
have the same phase and amplitude and thus “cancel.” Echoes
from moving targets generally do not have then same amplitude
and phase and so do not cancel. However if the target moves an
integer multiple of half wavelengths in one PRI, the phase of the
second echo is shifted by a multiple of 360 degrees from the first
and the echoes cancel. Such speeds are “blind speeds.” Changing
the PRI changes the blind speed. A PRI sequence is selected to
detect targets regardless speed Moving target detection (MTD)
radar systems use a doppler filter bank to divide the frequency
region between the PRF lines into several filter bands (for example:
8 bands). This requires repeated constant PRIs (say 10 pulses at
one PRI and then 10 pulses at another, etc.) Multiple PRIs are
required due to range and velocity ambiguities and make visible
target ranges and velocities “eclipsed” by transmitted pulses (in
23
time) or spectral lines (in frequency).
For constant PRI and RF, the maximum unambiguous range (Ru)
and the maximum unambiguous velocity (Vu) are given by:
Ru
c(PRI )
2
c
2( RF )( PRI )
Vu
Examples at 10 GHz:
PRI 1000 us, Vu=15 m/s and Ru=150 km
PRI 100 us, Vu=150 m/s and Ru=15 km
PRI 10 us, Vu=1500 m/s and Ru=1.5 km
As can be seen, the product of unambiguous range and velocity is a
constant. This means that the total ambiguity is fixed but changes
in PRI can increase the unambiguous range but decrease the
unambiguous velocity and vice versa.
c2
RuVu
24
4( RF )
13. 6
1 10
6
10
Inverse relationship of unambiguous
range and unambiguous velocity at
common radar frequencies
Rui 1
Rui 31 105
22
5M
Rui 4
1 .3
Rui 5
Rui 6
10
4
1 10
Rui 7
35
Rui 8
1000
15
GH
z
GH
z
GH
z
5 .5
3G
Hz
GH
z
42
5M
GH
z
Hz
Hz
3
1 10
10
10
3
100
4
1 10
1 10
Vui 1 Vui 2 Vui 3 Vui 4 Vui 5 Vui 6 Vui 7 Vui 8
10
25
Unambiguous Velocity (m/s)
Fi
2 7R
/V l it R l t d
Frequency
Agility Band
Frequency
Unambiguous Range (m)
Rui 2
(Depends
on
Component
Design,
ECM
Factors,
Designer
Ingenuity)
*
Coherent Processing Interval
(depends on radar mission)
Time
Determines Range Resolution
*BandwidthDepends on Radar Mission Which
Figure 2-8. Modern frequency Agile Radar with 100% Duty Factor
26
4
19. PRI STAGGER
Definition: Two or more discrete PRI intervals (elements) are alternating
in a periodic fashion.
T
• Desired Parameters
- Number of intervals
- Number of positions
- Interval values
- Sequence
- Stable sum
T
T
T
Unmodulated Pulse Train
T+
T-
T+
• Stagger Ratio
T-
Typical Staggered Pulse Train
Two Interpulse Intervals Shown
• Stagger Versus Jitter
37
RADARS WITH STAGGER
Radar
Pulse Width
(μs)
Average PRI
(μs)
Actual PRI’s Stagger Mode
(μs)
Stagger Ratio
Stagger Purpose
Radar Function
1.
6,18
100
2500
3500
5:7
To eliminate blind speeds
Surveillance
2.
4
3049
3032
3066
89:90
To eliminate blind speeds
Height Finder
3.
6
3000
2954.55
3045.45
0:97
(almost 100:103)
To eliminate blind speeds
Surveillance
4.
6
3000
2897
3103
613
1167
14:15
To eliminate blind speeds
Experimental surveillance
1000
5:7
5.
24
3000
2750
3250
11:13
To eliminate blind speeds
Surveillance
6.
3
1375
1250
1500
5:6
To eliminate blind speeds
Acquisition
7.
20
5247
5000
5494
0:91
(almost 10:11)
To eliminate blind speeds
Surveillance
8.
2
2777.9
2572.0
2777.8
2983.5
25:27:29
To eliminate blind speeds
Air route surveillance
9.
1.4, 4.2
1250
1240
1260
0.984
(almost 125:127)
To identify second-time-around pulses
Gap filter, surveillance and
interrogator
10.
2
2632-3226
Unknown
8-pulse stagger with three
programs
Unknown
To eliminate blind speeds
Air route surveillance
11.
42
1551.6
1408 (3)
1667 (3)
1460 (3)
Almost 1033:1225:1073
3 pulses at each interval for double
cancellation MTI to eliminate blind speeds
Detection; threat evaluation and
target designation (long range
mode given here)
12.
6.7
4000
3571.4 (3)
4405.1 (3)
3745.3 (3)
4255.3 (3)
4081.6 (3)
Exact order of 1 pulse
intervals is not known
3 pulse canceller for MTI. Stagger to
eliminate blind speeds
Surveillance
13.
1-100
400
62.1
2500
For first sequence only:
623.3
818.0
740.1
662.0
701.1
Various Sequences
16:21:19:17:20:18
16:17:16:17
16:19:16:19 38
16:21:16:21
16:17
To eliminate blind speeds. Has various
digital MTI processing including double
double-cancellation
Surveillance, tracking, kill
assessment, missile guidance
20. DESCRIPTION OF PRI VARIATIONS
Nature of Pulse-to-Pulse PRI Variations
Periodic
Discrete
Large
Type 1
Small
Random (non-periodic)
Continuous
Large
Small
3
Discrete
4
2
Large
5
Continuous
Small
6
Large
7
Small
8
(Large implies intentional, small implies incidental)
39
JITTERED PRI
Definition:
Pulse repetition intervals are intentionally varied on
interval-to-interval basis in a random or pseudorandom
fashion. The variations are usually more than one percent.
•
Intentional Jitter
- Discrete or continuous
•
Desired Measurements
- Mean PRI
- Peak PRI deviation limits
- PRI distribution (histogram)
- Number of discrete PRIs
40
21. RADARS WITH JITTER
PRI
(μs)
Pulse
Width
(μs)
Peak-to-Peak Jitter
(μs)
6, 18
3000
1000
505
26
4629
92.6
200
4000
50
20
5
400
10204
10204
6666
999.9
918.4
653.3
0.9
416-1515
(Variable)
4-50
4-2.67
500-2777.7
3.3-4.0
Peak-to-Peak Jitter
(%)
1.7
5
Radar Function
Anti-ECM and
interference
Target tracking
Anti-ECM and
interference
Long-range
surveillance
Random
Or
Programmed
Anti-ECM. Results from
PRF being submultiple
of RF which is jumping
Decoy discriminator
target tracking
acquisition
Unknown
Unknown
High resolution
synthetic aperture
mapping
Random
2.2-12
None
Sruveillance
Random
9.8
9.0
9.8
Anti-ECM and
interference
Random
20
20
60
Jitter Purpose
Random
3.75
83-303
Jitter Type
To reduced inward
range gate stealers, antiinterference, reduce
second-time around
echoes
Multifunction
41
PRI DWELL/SWITCH – PULSE DOPPLER
Definition:
Rapid (automatic) switching between discrete PRIs with a dwell at each PRI
PRI = T1
PRI = T2
Dwell Time 1
•
Dwell Time 2
Desired measurements
- Number of PRIs
- Value of PRIs
- Dwell times
- Total dwell time for sequence
- Dwell sequence
- Time to switch
42
22. SLIDING PRI
Definition: The pulse train has a PRI (PGRI) that is continuously changing in either
a monotonically increasing or decreasing manner between maximum
and minimum PRI limits.
•
Desired Parameters
- PRI limits (min and max)
- Sweep waveform
- Sweep time (limits)
43
OTHER PRI TYPES 1
•
Periodic Modulation
Definition:
Pulse train consists of discrete or continuous intervals that
periodically increase and decrease, e.g., with sinusoidal,
sawtooth or triangular waveform
- Modulating waveform and rate
- Mean PRI and peak deviation limits
•
Pulse Interval Displacement
Definition:
Insertion of a different pulse interval into an otherwise
periodic pulse train
- Displacement value
44
23. OTHER PRI TYPES 2
•
Interrupted Pulse Train
Definition:
Intentional interruption of the pulse train with no apparent periodicity
- Range of on-period
- range of off-period
•
Burst Pulse Train
Definition:
Pulse train that is transmitted for some purpose for a relatively short
time and then is off for a relatively long time
- Burst definition
- Number of bursts per second
- Relationships of burst to scan
45
SCHEDULED PRIs
•
Scheduled PRIs
Definition:
PRIs are computer controlled, vary with the target environment and
function being performed by radar, and cannot be described by other
definitions
- Number of intervals
- Interval values
- Typical sequences
- Reason for sequence
46
24. MUTLIPLE PULSE GROUPS
•
Constant and Cyclic Patterns
Definition:
Pulse group characteristics remain constant or vary cylically in
predictable manner
- Number of pulses in group
- Pulse intervals
- Group position data
•
Frames/formatted pulse trains (data encoded format)
Definition:
Pulse train includes marker and data pulses
47
SUMMARY OF PRI TYPES
Analysis p. 151
48
25. DOPPLER EFFECT
v = radial velocity
c = 3(108) m/sec
fo = transmitted RF
v
km/hr
FIGURE 3-1. DOPPLER EFFECT
f
1
fo
c v
c-v
Doppler Shift
fo
f
d
1
f
1
100
2v
c
fo
Doppler Shift (Hz)
@ 3 GHz
@ 10 GHz
555.5
1851.8
1000
fo
49
50
18518.5
2000
2v
c
5,555
11,111
37,037.0
27. FM THEORY
V(t)
A sin(2 f c t
(t))
Phase Disturbance
Total Phase
(t)
1 d
(total phase)
2 dt
Instantaneous Freq.
ASSUME
2 f ct
(t)
1 d
2 dt
fc
1d
2 dt
sin2 f m t
fm
cos2 f m t
Let
F/f m , then
1 d
2 dt
Fcos2 f m t
THEN :
V(t)
f
sin2 f m t)
fm
Asin(2 f c t
INDEX OF
53
MODULATION" M"
BESSEL EXPANSION
V(t)
A
Jo (m) sin c t
J (m) sin( c
1
J (m) sin( c
2
2 m )t
m )t
sin( c
J (m) . . . . .
3
J0(m)
J1(m)
J1(m)
J2(m)
J2(m)
fc-2fm
fc
fc+2fm
fc-fm
fc+fm
54
sin( c
2 m t)
m )t
28. BESSEL FUNCTIONS
55
MOD. INDEX LESS THAN 1
FOR COHERENT SIGNALS:
m
f
fm
1
J o (m) 1
J (m)
2
0
i.e. f is small
m
2
J (m)
1
J (m)
3
0 ....... etc.
THEREFORE
V(t)
A[sin c t
m
sin( c
2
A
m )t
m
sin( c
2
m )t]
V
SB
Vc
m
2
f
2f m
mA/2
mA/2
in dB
fc-fm
fc
V
20 log SB
Vc
fc+fm
56
20 log
f
2f m
29. EXAMPLES
20 log
f
2f m
f
2f m
40 dB
1 kHz
e.g. f m 1 kHz
f
20 Hz
IF f c 10 GHz, STABILITY IS
20 Hz
10 x 109 Hz
2 parts in 109
(AT 1 kHz RATE)
57
RANGE AMBIGUITY RESOLUTION VIA MULTIPLE PRIs
12 μs = X
T1 = 40 μs
2 μs = Y
T2 = 30 μs
Actual Round Trip Echo Time is T = 92 μs
N1 T1 + X = T
Trial and Error
Solution
and
N2 T2 + Y = T
N1
N2
N1 T1 + X
N2 T2 + Y
1
1
2
2
1
2
2
3
52
52
92
92
32
62
62
92
Unambiguous Range
c x Least Common Multiple of T , T
1 2
2
c x 120 s
2
58
Analysis p. 196
33. BIPOLAR VIDEO
65
DOPPLER RETURNS
TRAIN
CAR
Typical images displayed on TPS-25 ground
Surveillance radar. Shown are target images
of: 1) a train, 2) an automobile, 3) a walking man,
and 4) a walking girl. (US Army photograph.)
MAN WALKING
WOMAN
WALKING
66
34. PULSED-OSCILLATOR MTI
= 2E sin( fdT) cos [2 fd(t + T/2) +
Zeros at 0, , n
f
d
when
n
T
so blind speeds are V
b
c n
2RF T
n
2
Barton, p. 192
67
Page M50.ppt
68
PRF
o]
35. BLIND SPEED ELIMINATION
No Stagger
6
T
vb = n c/2(PRI)(RF)
T
T
1
T
Vbn = Vb (7 + 5)/2
5
7
Deep lobe
at 32/T
T
T
63
65
Null at
64/T
Ref: Barton, page 222
69
IMPROVEMENT FACTOR OF CANCELLER
I
(S/C)out
(S/C)
in
signal to clutter ratio at output of canceller
signal to clutter ratio at input of canceller
Overall improvement factor I is found from:
1
I
1
I
1
1
I
2
1
I
3
....
I1, I2, I3 are the individual improvement factors calculated on basis of PRI, pulse
amplitude, pulsewidth, transmitter frequency, ……….. stabilities
70
37. MTI + PULSE DOPPLER = MTD
Weighting
And
Magnitude
8-Pulse
Doppler
Filter Bank
3-Pulse
Canceller
I,Q Data
From A/D
Converters
Threshold
Zero
Doppler
Filter
Clutter Map
(Recursive
Filter)
Magnitude
(I2 + Q2)1/2
Typical Applications
New FAA ASR radars (10 pulse dwell)
AN/SPS-49 USN-adjunct to AEGIS (6-pulse dwell)
RAMP (Canada)
Clutter
Memory
15 – 20 radar scans are
needed to establish
the clutter map
73
MTD PERFORMANCE
• Theoretical
RMS Clutter Width
Processor
0.01 PRF
0.1 PRF
MTI Improvement
Factor
1 canceller
2 cancellers
3 cancellers
25 dB
50 dB
72 dB
8 dB
12 dB
16 dB
FFT Improvement
Factor
8 pulses
35 dB
22 dB
MTI + FFT
Improvement Factor
1 canceller +
8 pulse FFT
2 cancellers +
8 pulse FFT
3 cancellers +
60 dB
28 dB
80 dB
34 dB
100 dB
36 dB
(Reference: NRL Report 7533, G.A. Andrews, Jr.)
• Practical
Performance of FAA ASR radar: 3 pulse MTI alone 25 dB
3 pulse MTI + 8 pulse FFT
45 dB
(Reference: Skolnik, Introduction to Radar Systems, 1980, p. 127-128)
74
Target
Detection
38. ELINT IMPLICATIONS OF MTD
• Coherent carrier
RF stability is necessary
• Constant PRIs
Constant RF
(for a certain
number of pulses)
Several PRIs of the same interval must be
transmitted at the same RF (typically 4,
8, or 16 pulses for the FFT plus pulses
to fill the canceller. For example, a
three-pulse canceller plus an eight-pulse
FFT requires 10 pulses).
• “Stagger” to eliminate
blind speeds
For these radars, the pulse interval
stagger occurs not from pulse-to-pulse but
from pulse group-to-pulse group
• Long PRI
MDT is generally used for long-range radars
where the low PRF creates very ambiguous
Doppler shifts.
75
PRI EXERCISES
1.
The analyst found a signal at 6 GHz which had two-interval, two-position stagger. The
intervals were 500 and 550 microseconds. What is the average PRI? What is the
stagger ratio? What is ? What are the new blind speeds?
2.
What is the improvement factor for MTI of a radar which has RMS jitter of 10 nanosec
and a pulse duration of 1.41 microsec?
3.
A discrete random jitter PRI train was analyzed and the PRIs were found to be one of
the following 5 nominal values:
Nom
PRI (μsec)
2440.8
2428.7
2465.3
2453.1
2562.9
Is there a clock? If so, what countdowns are used and what is the clock frequency or
period? What common range mark is that closest to?
(This problem is discussed on p. 194-195 of analysis book.)
76
39. PRI EXERCISES #2 - ANSWERS
1.
(500 + 550)/2 = 525 microsec = average PRI
R = 550/500 = 1.1 (11:10)
= 550 – 525 = 25 microsec
Blind speed before stagger = nc/(2 • PRIave • RF)
(3 x 108 ) m / sec
VB
171.4 km / hr (106.5 mph )
2(525)(10 6 ) sec x 6(109 ) x 1 / sec
V/VB = (11 + 10/2 = 10.5)
V = (10.5) (171.4) = 1800 km/hr (1118.4 mph)
2.
Improvement factor due to PRI instability is:
IdB = 20 log [ / 2 t B )],
B = bandwidth
= jitter, = pulse duration,
2
IdB = 20 log [1.41 (10-6) sec/ 2 • 10(10-9)sec)]
= 20 log [102] = 40 dB
3.
Period
2440.8
2428.7
2465.3
2453.1
2562.9
Periods
In Order
2482.7
2440.8
2453.1
2465.3
2562.9
Difference
12.1
12.3
12.2
97.6
Nearest
Countdown
199
200
201
202
210
Calculated
Clock Period
12.20452
12.20400
12.20447
12.20445
12.20428
12.204392 average
The differences 12.1, 12.3, 12.2 average 12.2
97.6 divided by 12.1 = 8
So use 12.2 to start for countdowns.
The average clock period is 12.204392 μsec so reciprocal is 81.93777 kHz (2000 yards, see p. 192.)
77
NOISE EFFECT ON PRI
Triggering Error
T
T
RISE
0.8
A
A
A
A
T
Noise
A
T
TRISE/0.8
78
Slope
A
(TRISE / 0.8)
40. PRI VARIATION DUE TO NOISE
2
amplitude Noise Power
1
(Amplitude)2 Signal Power SNR
T
Rise 1
Time
0.8 SNR
2
2
2
2 2
PRI
Time1
Time 2
Time
T
2 Rise
PRI 0.8 SNR
79
BANDWIDTH EFFECT ON SNR
SNR 3.125
tr
PRI
2
tr
.35
Bandwidth
SNR Required for
Bandwidth (MHz)
Rise Time
Limit (ns)
1 ns Jitter
10 ns Jitter
100 ns
Jitter
0.1
3.5 s
81 dB
61 dB
41 dB
1.0
0.35 s
61 dB
41 dB
21 dB
10.0
35 ns
41 dB
21 dB
X
100.0
3.5 ns
21 dB
X
X
80
42. PERFORMANCE OF TRIGGER CIRCUIT
83
DOPPLER SHIFT OF PRI
•
In 1 PRI, the platform moves
VR • PRI
•
Transmit time from transmitter to receiver changes by VR • PRI/c
•
Example: VR = 600 M/S PRI = 3000 μs
3
Observed PRI = 600 x 3 x 10
3 x 108
84
6 ns
43. DELAY AND PULSE JITTER
Delay D2
Delay D1
Peak-to-Peak Jitter
At Delay D1
Peak-to-Peak Jitter
At Delay D2
85
DELAYED SWEEP JITTER PHOTOS
~ 1 μs Jitter
Delay = 1 PRI
~ 2 μs Jitter
Delay = 5 PRI
86
52. ACTIVITY IN 0.1S INTERVALS
103
INTERVALS FORMED BY
PULSE PAIRS
104
53. DELTA-T HISTORGRAM
(10% JITTER)
105
DELTA-T HISTOGRAM-STAGGER
•••
4
t0 = 0
5
t1 = 4
7
4
t2 = 9
t3 = 16
A.
C.
(tn – tn-3) = 16
D.
t6 = 27
(tn – tn-5) = 25, 27, or 2
F.
t5 = 25
4
(tn – tn-4) = 20, 21 or 23
E.
1 2
(tn – tn-2) = 9, 11 or 12
t4 = 20
7
(tn – tn-1) = 4, 5 or 7
B.
5
(tn – tn-6) = 32
3
4
5
(4 + 5, 4 + 7, 5 + 7)
(4 + 5 + 7)
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
A
B
C
D
106
E
F
5
t7 = 31
•••
t7 = 37
54. THREE POSITION STAGGER
107
DELTA-T HISTOGRAM:
TOA AUTOCORRELATION
n
f (t )
n 1
(t
tn )
.....
t1
t2 . . . . .
h( )
h( )
f (t ) f t
tn )
n
(t
tn
tk
0
tk
tn
k
value only if t
EXAMPLE
t1
t4 . . . . .
dt
(t
t3
0 and
OR t n
t = t2
tk
t3
t=0
t = t1 +
) dt
108
t4
55. DELTA-T HISTOGRAM:
TOA AUTOCORRELATION
h( )
2
n k
h( )
1
(t n
t
2
)
k
(t n
n k
1
t
k
)
A count of the number of
pulse pairs such that
1
tn
t
k
2
THEREFORE:
A count of the number of pairs of pulses whose arrival
times differ by a value between 1 and 2 is equal to
the integral of the autocorrelation of the TOA’s
109
JITTER ANALYSIS MODEL
Center Frequency
(average PRF)
Jitter
Waveform
Peak
Amplitude
FM
Oscillator
Trigger
Generator
Periodicities
• Periods
• Amplitudes
Drifts/Trends
• Slopes
Random Components
• Bandwidths
• Variances
• Probability Densities
110
Time of
Arrival
Sequence
60. EFFECT OF A NEAR MULTIPLE PRI
119
EFFECTS OF JITTER ON DELTAHISTOGRAMS
120
61. Delta-T Histogram for Ten Interleaved Pulse Trains
Delta-T Histogram
Histogram Count
100
dhist b
.75 max( dhist )
50
0
5
8 10
1 10
4
1.2 10
4
1.4 10
int vb PRI k 10
4
1.6 10
4
6
PRI, Seconds
N
820
10 Interleaved Pulse Trains
121
Comparison of the Delta-T and Complex Delta-T Histograms
Comparing Delta-T Histograms
100
100
abchist b
dhist b
0
1.05 max( abchist )
1.05 max( dhist )
50
100
0
1 10
4
2 10
4
3 10
int vb PRI k 10
N
820
6
4
4 10
int vb PRI k 10
PRI, Seconds
4
6
10 Interleaved Pulse Trains
Top Trace is the regular Delta-T Histogram;
Bottom Trace is the Complex Delta-T Histogram--Note how multiples of the PRIs are suppressed
The dots above the peaks indicate the true PRI values
122
Delta-T Hisotgram bin Count
Complex Histogram Absolute Value
150
62. Effect of Jitter on Delta-T Histograms
(Jitter=1 microsecond)
Comparing Delta-T Histograms
abchist b
1.05 max( abchist)
dhist b
0
50
1.05 max( dhist )
50
0
5
5 10
1 10
4
4
1.5 10
2 10
4
intv b PRI k 10
2.5 10
6
4
4
3 10
intv b PRI k 10
3.5 10
100
4
6
PRI, Seconds
Jitnc
0
0.5
Jitcum
0
0.5
N
820 width
5
10
7
10 Interleaved Pulse Trains
123
Effect of Jitter on Delta-T Histograms
(Jitter=2 microseconds)
Comparing Delta-T Histograms
100
100
50
dhist b
abchist b
1.05 max( abchist)
0
50
1.05 max( dhist )
50
0
5
5 10
1 10
4
1.5 10
4
2 10
4
intv b PRI k 10
2.5 10
6
4
3 10
intv b PRI k 10
4
3.5 10
4
100
6
PRI, Seconds
Jitnc
0
1
Jitcum
0
1
N
820 width
124
5
10
7
10 Interleaved Pulse Trains
Delta-T Hisotgram bin Count
Complex Histogram Absolute Value
Complex Histogram Absolute Value
50
Delta-T Hisotgram bin Count
100
100
63. Effect of Jitter on Delta-T Histograms (Jitter=5 microseconds)
Comparing Delta-T Histograms
100
50
dhist b
abchist b
1.05 max( abchist)
50
0
1.05 max( dhist )
50
0
5
5 10
1 10
4
1.5 10
4
2 10
4
intv b PRI k 10
2.5 10
6
4
3 10
intv b PRI k 10
4
3.5 10
4
Delta-T Hisotgram bin Count
Complex Histogram Absolute Value
100
100
6
PRI, Seconds
Jitnc
0
2.5
Jitcum
0
2.5
N
820 width
5
10
7
10 Interleaved Pulse Trains
125
Complex Delta-T histogram: Original and Improved
Original Complex Delta-T Histogram
Improved Complex Delta-T Histogram
Uniform Jitter=0.002
Uniform Jitter=0.02
Shift time origin
To avoid excessive
Phase variation
Uniform Jitter=0.2
126
K Nishiguchi and M. Korbyashi,
"Improved Algorithm for
estimating Pulse Repetition
Intervals,” IEEE Transactions on
Aerospace and Electronic Systems,
Vol. 36, No. 2, April 2000.
64. Example of Automated Peak Processing Results
Delta-T Hist.
Complex Delta-T
Input PRI Values
0
0
0
1
2
0
1
2
1. 15·10-4
1. 162· 10-4
1. 176· 10-4
1. 19·10-4
3
4
5
6
1. 15·10-4
1. 164· 10-4
1. 178· 10-4
1. 192· 10-4
7
8
9
10
11
1. 21·10-4
1. 23·10-4
1. 26·10-4
0
0
7
8
9
10
11
1. 21·10-4
1. 23·10-4
1. 26·10-4
0
0
12
13
14
15
0
0
0
0
12
13
14
15
0
1· 10-4
1. 05·10-4
1. 11·10-4
3
4
5
6
pk
1· 10-4
1. 048· 10-4
1. 11·10-4
0
0
0
0
pkc
0
1
6
2
3
4
5
6
1. 11·10-4
1. 15·10-4
1. 163· 10-4
1. 177· 10-4
1. 191· 10-4
7
8
9
PRI 10
1· 10-4
1. 05·10-4
1. 21·10-4
1. 23·10-4
1. 26·10-4
This example based on the method of B.
Frankpitt, J. Baras, A. Tse, "A New Approach
to Deinterleaving for Radar Intercept
Receivers," Proceedings of the SPIE, Vol
5077, 2003, pages 175-186
Jitter =10 ns cumulative and 10 ns non-cumulative
Histogram Bin size 200 ns.127
Pulse Train Spectrum of Ten Interleaved Pulse Trains
k
Amplitude
PRF Spectrum
0.01
Xj
0.00011 max( X)
0.005
0
6000
8000
4
1 10
1.2 10
4
1.4 10
f j PRF k
N
8.705
3
10
PRF (Hz)
10 Interleaved pulse Trains
PRF Resolution 10 Hz
128
4
1.6 10
4
1.8 10
4
2 10
4
This plot is the FFT of
TOA
phase 2 (
)
T
R. Orsi, J. Moore and R. Mahony, "Interleaved
Pulse Train Spectrum Estimation," International
Symposium on Signal Processing and its
applications, ISSPA, Gold Coast, Australia,
August 25-30, 1996
65. k
PRF Spectrum
Amplitude
0.03
Xj
.025 0.02
.015
0.01
0
4000
6000
8000
4
4
1 10
1.2 10
1.4 10
4
1.6 10
4
1.8 10
4
4
2 10
f j 1 PRF k 2 PRF k
PRF (Hz)
10 Interleaved pulse Trains
N
1.741
3
10
Fewer Pulses--Degraded PRF Resolution (50 Hz)
129
Figure 13.10 Pulse Train Spectrum for a Shorter Record
k
PRF Spectrum
Amplitude
0.03
Xj
.03
0.02
.02
0.01
0
4000
6000
8000
4
4
1 10
1.2 10
4
1.4 10
4
1.6 10
f j 1 PRF k 2 PRF k
PRF (Hz)
10 Interleaved pulse Trains
N
871
Fewer Pulses--Degraded PRF Resolution (100 Hz)
130
4
1.8 10
4
2 10
66. PULSE SORTING ALGORITHM
C
C
C
B
B
C
B
B
B
B
B
B
B
A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A
A A
3 Adjacent Matching Intervals
Step 1. Find 3 adjacent matching intervals
Step 2. Extend in both directions to discover other numbers of the pulse train
Step 3. Remove this pulse train and go back to Step 1.
If no more pulses can be removed, go to Step 4.
Step 4. Consider all pairs of pulses to search for intervals which match; go to Step 2.
131
SORTER SOFTWARE PERFORMANCE
Score
Amp On
(Pulses Pr ocessed) 10 (Pulses Wrong)
Total Pulses Noise Pulses
Amp On: 0.2 amp Tolerance
from pulse-to-pulse
0% Jitter
100
90
Amp Off
80
n
1% Jitter
f
Of
mp
A
70
Score
pO
Am
60
50
pO
Am
Simulated Data
Average Density 200 pps
40
n
Amp Off
30
20
8% Jitter
10
0
1
10μs
100μs
132 Tolerance
Time
1000μs
70. PRI ANALYSIS EXERCISE
Two signals are observed with the same angle of arrival but on different frequencies. The PRI of one is nearly
stable at 3000 μs. The PRI of the second jitters randomly with a mean value of 1500 μs and a peak-to-peak jitter
of about 20 μs. The analyst notices that the PRI’s of the second signal can be paired such that their sum is nearly
stable at 3000 μs; i.e., PRI #1 + PRI #2 = PRI #3 + PRI #4 = PRI #5 + PRI #6, etc. However, PRI #2 + PRI #3
PRI #4 + PRI #5. He also notices that the mean value of the second signal’s PRI is exactly one-half that of the
first signal’s PRI every time the two signals are reported. The first signal has a slow circular scan, the second a
faster sector scan. What conclusions might be drawn about these two radars?
What additional data would you request from the ELINT station?
139
PRI EXERCISE ANSWER
There is a good possibility that the second radar operates in PRI synchronism with
the first;
but at one-half the PRI. Alternate pulses are triggered by the master clock, the
intermediate
pulses are generated by “one shot” type delay circuit which is not stable.
The second radar may be a height finder using elevation sector scan and associated
with a long
range search radar.
Confirmation of this would be aided by using two receivers and making a recording
of both
Signals simultaneously to investigate whether the second signal is synchronized to the
first.
140
71. PRECISION PDWs
• Pulse Descriptor Words are computed from pre-detection
burst recordings
• Digitizer has “detected” presence of high SNR pulses,
and captured them
• Different capture and processing techniques apply to low
SNR pulses
• Standard PDWs computed are:
- Amplitude
- Frequency
- Time of Arrival - Bandwidth
- Pulse Width
• Algorithms and accuracies are described
141
Condor Systems, Inc.
USEFULNESS OF PRECISION PDWs
• Reveals fine details of pulse train jitter patterns
• Permits very high accuracy computation of crystal
controlled PRIs with few pulses
• Can use very accurate pulse width to sort pulses
• Fine variations of frequency pulse to pulse reveal unique
emitter characteristics (e.g., frequency pulling effects due
to VSWR changes in antenna rotary joint, etc.)
• Amplitude droop in transponder pulse groups
• Precise antenna pattern scan envelope measurement
142
Condor Systems, Inc.
72. EXAMPLE OF PRE-DETECTION RADAR
PULSE RECORDING
143
Condor Systems, Inc.
CALCULATION OF AMPLITUDE, TOA,
PW
144
Condor Systems, Inc.
73. TOA MEASUREMENT ACCURACIES
• Digitizer time base determines ultimate accuracy
• Individual pulse time of arrival error determined by:
t
where
tr
2SNR
t RMS Error in TDOA
t r Pulse Rise Time
SNR Signal to Noise Ratio in Captured
Pulse Bandwidth
• Example: 30 ns rise time, 37 dB SNR yields RMS error of
300 picoseconds per pulse
145
Condor Systems, Inc.
PULSE WIDTH MEASUREMENT
ACCURACY
pw
where
t2
r
t2
f
pw RMS error in pulse width
t r RMS error of pulse risin g edge time
t
RMS error of pulse falling edge time
f
Example: RMS errors of captured pulse edge times of
300 picoseconds yield 1.414 x 300 = 423
picoseconds RMS pulse width error per pulse.
Condor Systems, Inc.
146
74. EXAMPLE OF PULSE WIDTH
ACCURACY
147
Condor Systems, Inc.
PULSE FREQUENCY COMPUTATION
148
Condor Systems, Inc.
75. PULSE FREQUENCY ACCURACY
1
T SNR TW
in
f
• Technique applies to high SNR cases (+15 dB), sine
wave pulse
where
f
T
RMS frequency accuracy
Integration time (~ pulse width)
SNR
Input Signal to Noise Ratio in BW , W
in
W
Input Pr e det ection bandwidth
Example: 1 microsec pulse, 30 dB SNR, 20 MHz Bandwidth
yields RMS accuracy of 7 kHz.
Condor Systems, Inc.
149
EXAMPLE OF PULSE FREQUENCY
COMPUTATION
150
Condor Systems, Inc.