This document describes the development of a low-power wireless sensor network for monitoring carbon dioxide (CO2) levels. It consists of laser spectroscopic sensor nodes that measure CO2 concentrations with high sensitivity and selectivity. Laboratory tests showed temperature induced drift affecting long-term sensor performance. The researchers stabilized sensor temperature in a controlled chamber, eliminating drift. They demonstrated a proof-of-concept two-node network operating continuously for 8 hours, with the data revealing details about human activity levels in the lab over time. Future work includes developing real-time calibration to address drift and deploying a large-scale field network for long-term trace gas monitoring.
This document describes a wireless sensor network for monitoring environmental carbon dioxide (CO2) levels using laser-based sensor nodes. The network aims to provide high spatial resolution real-time CO2 concentration data with unprecedented sensitivity and selectivity. Laboratory and field tests of a two-node and three-node network demonstrated the long-term stability and cross-correlation performance of the sensor nodes, which achieved temperature drift correction. Future work involves deploying a larger sensor network for long-term trace gas monitoring in environmental field studies.
A Solar-powered, TDMA Distributed Wireless Network for Trace-gas MonitoringClinton Smith
This document summarizes a presentation on developing a solar-powered wireless sensor network for monitoring trace gases like carbon dioxide (CO2). Key points:
1) The network uses tunable diode laser absorption spectroscopy sensors with herriott cells and wireless nodes to measure CO2 at various locations around Princeton University.
2) Field tests captured localized CO2 variations at different nodes and validated measurements against commercial sensors.
3) The autonomous solar-powered sensor nodes can help characterize diverse CO2 sources and sinks better than conventional techniques.
4) Future work includes implementing multi-hop networking for wider coverage and exploring 3G connections between nodes.
This document discusses several topics related to optical fiber communication systems including:
1. Factors that limit the performance of amplified fiber links such as transmission distance, data rate, and component costs.
2. System requirements including transmission distance, data rate, fiber type, and receiver sensitivities.
3. Key components of fiber optic systems and their specifications including lasers, detectors, and other elements.
4. Performance limiting factors for terrestrial and undersea lightwave systems.
5. Physical phenomena that degrade receiver sensitivity in realistic lightwave systems including modal noise and dispersion broadening.
This summary provides the key details from the document in 3 sentences:
The document discusses troubleshooting methods for improving microwave links used by TATA DOCOMO in India. It proposes a system to control the power of indoor units using water sensors and control diesel generators using auxiliary ports. The document also describes the various acknowledgment alarms generated in NEC microwave systems and their associated troubleshooting methods to reduce call drops.
This document discusses a phase locked loop (PLL) circuit that can recover a clock signal from USB data without using a crystal oscillator as a reference.
It begins by outlining the USB specification and challenges of clock recovery from USB data. It then introduces an adaptive PLL architecture that can control its loop bandwidth to enhance locking performance.
The circuit implementation is described, using a Hogge phase detector to extract the clock signal from the non-return-to-zero (NRZI) encoded USB data. Simulation results show the circuit can recover the 48MHz clock within 10 seconds, meeting USB specifications.
This document summarizes the performance measurements taken on a 40-channel 10G DWDM system operated by Bharath Sanchar Nigam Limited in India. The key findings were:
1. Optical power levels were measured for each channel at different points in the system. Some channels showed power levels indicating a fault in the respective fiber cable.
2. Parameters like noise figure, gain, polarization mode dispersion and dispersion were analyzed to identify limitations and suggest improvements to optimize the system.
3. Nonlinear impairments like four-wave mixing, self-phase modulation and stimulated Raman/Brillouin scattering were also evaluated to determine their impact based on number of channels, channel power, and fiber properties
The document outlines a course on fiber-optic communication systems, discussing the history and evolution of the technology from electrical to optical systems, describing key components like transmitters, receivers, and modulation formats, and explaining limiting factors in optical fibers like loss, dispersion, and nonlinearities that must be managed for high-speed data transmission.
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Close
This document describes a wireless sensor network for monitoring environmental carbon dioxide (CO2) levels using laser-based sensor nodes. The network aims to provide high spatial resolution real-time CO2 concentration data with unprecedented sensitivity and selectivity. Laboratory and field tests of a two-node and three-node network demonstrated the long-term stability and cross-correlation performance of the sensor nodes, which achieved temperature drift correction. Future work involves deploying a larger sensor network for long-term trace gas monitoring in environmental field studies.
A Solar-powered, TDMA Distributed Wireless Network for Trace-gas MonitoringClinton Smith
This document summarizes a presentation on developing a solar-powered wireless sensor network for monitoring trace gases like carbon dioxide (CO2). Key points:
1) The network uses tunable diode laser absorption spectroscopy sensors with herriott cells and wireless nodes to measure CO2 at various locations around Princeton University.
2) Field tests captured localized CO2 variations at different nodes and validated measurements against commercial sensors.
3) The autonomous solar-powered sensor nodes can help characterize diverse CO2 sources and sinks better than conventional techniques.
4) Future work includes implementing multi-hop networking for wider coverage and exploring 3G connections between nodes.
This document discusses several topics related to optical fiber communication systems including:
1. Factors that limit the performance of amplified fiber links such as transmission distance, data rate, and component costs.
2. System requirements including transmission distance, data rate, fiber type, and receiver sensitivities.
3. Key components of fiber optic systems and their specifications including lasers, detectors, and other elements.
4. Performance limiting factors for terrestrial and undersea lightwave systems.
5. Physical phenomena that degrade receiver sensitivity in realistic lightwave systems including modal noise and dispersion broadening.
This summary provides the key details from the document in 3 sentences:
The document discusses troubleshooting methods for improving microwave links used by TATA DOCOMO in India. It proposes a system to control the power of indoor units using water sensors and control diesel generators using auxiliary ports. The document also describes the various acknowledgment alarms generated in NEC microwave systems and their associated troubleshooting methods to reduce call drops.
This document discusses a phase locked loop (PLL) circuit that can recover a clock signal from USB data without using a crystal oscillator as a reference.
It begins by outlining the USB specification and challenges of clock recovery from USB data. It then introduces an adaptive PLL architecture that can control its loop bandwidth to enhance locking performance.
The circuit implementation is described, using a Hogge phase detector to extract the clock signal from the non-return-to-zero (NRZI) encoded USB data. Simulation results show the circuit can recover the 48MHz clock within 10 seconds, meeting USB specifications.
This document summarizes the performance measurements taken on a 40-channel 10G DWDM system operated by Bharath Sanchar Nigam Limited in India. The key findings were:
1. Optical power levels were measured for each channel at different points in the system. Some channels showed power levels indicating a fault in the respective fiber cable.
2. Parameters like noise figure, gain, polarization mode dispersion and dispersion were analyzed to identify limitations and suggest improvements to optimize the system.
3. Nonlinear impairments like four-wave mixing, self-phase modulation and stimulated Raman/Brillouin scattering were also evaluated to determine their impact based on number of channels, channel power, and fiber properties
The document outlines a course on fiber-optic communication systems, discussing the history and evolution of the technology from electrical to optical systems, describing key components like transmitters, receivers, and modulation formats, and explaining limiting factors in optical fibers like loss, dispersion, and nonlinearities that must be managed for high-speed data transmission.
Back
Close
This document analyzes the design of a portable video transceiver system. It begins by outlining typical applications of portable video transmission like live news reporting from remote areas. It then presents the key parameters in the design of such a system, including transmitted power, path loss, foliage loss, rain attenuation, and noise power. The document develops mathematical models and formulas for each parameter. It describes field experiments conducted to measure actual path loss. Finally, it presents a block diagram of a simulation model that can optimize the design parameters to meet user requirements like communication range and video quality.
Impact of Vibration on a Computer Network Using Optical Fibre CablesPremier Publishers
This study was carried out to validate the negative impact of vibration on a computer network using optical fibre cables where the optical time–domain reflectometer (OTDR) of single mode configuration was employed to acquire signal losses on the network. The losses were categorized in three data sets such as that from a non–vibration (NV), a vibration source from a shaker and generator (SHG) and another source combining the shaker, generator, and a truck (SHGT). The impact of these results were compared on a column and area graph where we obtained a superimposed effect combining all data sets in the area graph that the vibration sources from SHGT had greater impact on the network as their reflected losses were -33.31dB, -33.29dB, and -33.34dB respectively for NV, SHG, and SHGT. The results further confirmed that signal losses on the network has a direct relationship with distance and also, vibration can as well help to normalize errors arising from poorly terminated cables and correct some splice faults as number of events an OTDR records are limited. This study also confirmed the possible use of this system to investigate underground movements likely to be earthquakes or road failure signs.
Dispersion Compensation Module for WDM -PON at 5 -GB/S Downstream with Variou...IRJET Journal
This document discusses dispersion compensation in wavelength division multiplexing passive optical networks (WDM-PONs) operating at 5 Gbps downstream transmission. It simulates various modulation formats, including duobinary, differential phase shift keying (DPSK), and on-off keying (OOK) to increase data speeds over different transmission distances. The combination of 87.5 km standard single mode fiber and 12.5 km dispersion compensating fiber is used to transmit over a total of 100 km while maintaining a low bit error rate and high Q factor. Dispersion compensation fibers are employed to counteract chromatic dispersion accumulated over long reaches of single mode fiber.
This document summarizes the design and testing of a 2.4 GHz microstrip patch antenna with a single slot for wireless local area network (WLAN) applications. The antenna was designed to improve the bandwidth and performance of conventional microstrip patch antennas. Simulation results showed a return loss of -37.5 dB and an impedance bandwidth of 2.3-2.6 GHz. Experimental testing agreed with simulations. The antenna achieved a gain of 5 dB and has applications in mobile communications, satellite communications, and wireless personal area networks due to its compact size, broadband capability, and high gain.
A 3-10 GHz Ultrawideband SiGe LNA with Wideband LC Matching NetworkRFIC-IUMA
Publicated in The International Society for Optical Engineering’s –
Microtechnologies for the New Millennium Design
(VLSI Circuits and Systems Conference),
Gran Canaria, España, 2007
In-band OSNR Monitoring Technique based on Brillouin Fiber Ring LaserDavid Dahan
We propose an improved technique for in-band OSNR monitoring based on a Brillouin fiber ring laser seeded by the optical channel to be monitored. This technique shows a reduction of the required input power into the monitor along with a large and tunable dynamic OSNR monitoring range. It is demonstrated experimentally and numerically for various bit rates and modulation formats
This document presents research on using a microstrip patch antenna as a sensor for electromagnetic interference (EMI) measurements. It describes how the antenna factor of the microstrip patch antenna was estimated through both simulations using CST Microwave Studio software and experimental measurements. The antenna factor relates the incident electric field to the received voltage and is an important parameter for EMI sensors. Simulation and experimental results showed good agreement for the estimated antenna factor versus frequency characteristics of the microstrip patch antenna, demonstrating its potential as an alternative EMI sensor.
The document discusses the use of optical fiber sensors for non-destructive testing applications. It notes that fiber optic sensors are well-suited for structural health monitoring due to their small size, light weight, and immunity to electromagnetic interference. The document outlines different types of fiber optic sensors and their advantages over conventional sensors. It also provides examples of how fiber optic sensors can be embedded in composite materials and structures to monitor factors like temperature, pressure, and strain for non-destructive testing.
The document outlines the contents of microwave and optical fiber lab experiments, including experiments measuring characteristics of devices like Gunn diodes, klystrons, and optical fibers as well as calibrating attenuators and measuring antenna patterns. It also provides descriptions of the components and functioning of an optical fiber trainer kit, including fiber preparation and characteristics of transmitters, receivers, and other devices used in optical communication experiments.
Transmission system used for optical fibers Jay Baria
In this presentation I have explained various types of transmission system used for optical transmission and also described about the budget method that has to be followed while selecting an source for optical fibers and also about the factors that should be consider while selecting an source.
Optical Fiber Communication Part 3 Optical Digital ReceiverMadhumita Tamhane
Current generated by photodetector is very weak and is adversely effected by random noises associated with photo detection process. When amplified, this signal further gets corrupted by amplifiers. Noise considerations are thus important in designing optical receivers.
Most meaningful criteria for measuring performance of a digital communication system is average error probability, and in analog system, it is peak signal to rms noise ratio. ...
Future Position X is a leading European cluster for innovative use of geographical information. It brings together research labs, markets, and networks to create new solutions for tomorrow's society and emerging markets. This drives growth through new services, products, companies, and jobs.
This document describes 5 experiments related to fiber optic communication:
1. Studied the relationship between an input analog signal and received signal over 650nm fiber. Signals remained the same.
2. Studied digital fiber link. Input square wave was transmitted and received successfully.
3. Studied intensity modulation using an analog input. Signal was modulated, transmitted, demodulated and amplified back to original.
4. Studied intensity modulation using a digital input. Signal was modulated and reconstructed at receiver.
5. Described a frequency modulation system. A 1kHz sine wave frequency modulated a digital signal, which was transmitted and demodulated to recover the original signal.
The document is an optical communication lab manual that outlines 8 experiments on optical fibers and fiber optic communication. Experiment 1 involves demonstrating different types of optical fibers and connectors. Experiment 2 establishes a 650nm fiber optic analog link. Experiment 3 establishes a 650nm digital fiber optic link. Experiment 4 studies intensity modulation using an analog input signal, transmitting it over fiber, and demodulating the output. Experiment 5 is similar but uses a digital input signal.
A directional coupler is used to combine and split optical signals. It consists of two input ports and two output ports. A 2x2 coupler splits the power from each input port between the two output ports. Star couplers combine multiple signals and broadcast them to many outputs. Isolators allow transmission in one direction but block transmission in the opposite direction, while circulators transmit signals between ports in a circular fashion. Multiplexers and demultiplexers combine and separate different wavelengths in WDM systems using interference filters such as arrayed waveguide gratings.
This presentation presents an overview of fiber optic sensor technology ,basic classifications of optic sensors, the basic functions of optical fiber sensors and also discusses the two important fiber optic sensors , namely the Mach - Zehnder interferometric fiber sensor and the fiber optic gyroscope.
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN ApplicationsSaou-Wen Su
A simple, bent monopole antenna well useful for WLAN applications in the 2.4 GHz band is presented. The monopole antenna has a rectangular radiating plate in general and is short-circuited to a small antenna ground and an assembly plate. The assembly plate is not only used as a supporting plate for antenna installation but also regarded as antenna ground. With a low profile of the monopole and use of the coaxial-line feed, the antenna has much flexibility in the placement inside a wireless device. Good radiation characteristics have been observed too.
This document discusses various optical components used in fiber optic communication systems. It describes passive components like couplers, isolators, filters, and multiplexers/demultiplexers. It also covers active components such as modulators, switches, optical amplifiers, and wavelength converters. Different technologies for implementing these components are presented, including micro-optics, integrated optics, fiber-based, and hybrid approaches. Key parameters and requirements for optical components are also outlined.
An Adaptive Energy Efficient Reliable Routing Protocol for Wireless Sensor Ne...IDES Editor
A reliable routing protocol for wireless sensor
networks (WSN) should be capable of adjusting to
constantly varying network conditions while conserving
maximum power. Existing Routing protocols provide
reliability at the cost of high energy consumption. In this
paper, we propose to develop an Adaptive Energy Efficient
Reliable Routing Protocol (AEERRP) with the aim of
keeping the energy consumption low while achieving high
reliability. In our proposed protocol, the data forwarding
probability is adaptively adjusted based on the measured
loss conditions at the sink. So only for high loss rates, a node
makes use of high transmission power to arrive at the sink.
Whenever the loss rate is low, it adaptively lessens the
transmission power. Since the source rebroadcasts the data,
until the packet loss is minimized, high data reliability is
achieved. By simulation results we show that the proposed
protocol achieves high reliability while ensuring low energy
consumption and overhead.
The document describes the development of a low-power portable laser spectroscopic sensor for atmospheric CO2 monitoring using tunable diode laser absorption spectroscopy, including the design of the sensor which is housed in an enclosure smaller than a shoebox, laboratory tests showing the sensor can accurately detect changing CO2 concentrations from soil and animal respiration, and field tests demonstrating the sensor's ability to measure forest floor respiration across a wireless sensor network.
This document analyzes the design of a portable video transceiver system. It begins by outlining typical applications of portable video transmission like live news reporting from remote areas. It then presents the key parameters in the design of such a system, including transmitted power, path loss, foliage loss, rain attenuation, and noise power. The document develops mathematical models and formulas for each parameter. It describes field experiments conducted to measure actual path loss. Finally, it presents a block diagram of a simulation model that can optimize the design parameters to meet user requirements like communication range and video quality.
Impact of Vibration on a Computer Network Using Optical Fibre CablesPremier Publishers
This study was carried out to validate the negative impact of vibration on a computer network using optical fibre cables where the optical time–domain reflectometer (OTDR) of single mode configuration was employed to acquire signal losses on the network. The losses were categorized in three data sets such as that from a non–vibration (NV), a vibration source from a shaker and generator (SHG) and another source combining the shaker, generator, and a truck (SHGT). The impact of these results were compared on a column and area graph where we obtained a superimposed effect combining all data sets in the area graph that the vibration sources from SHGT had greater impact on the network as their reflected losses were -33.31dB, -33.29dB, and -33.34dB respectively for NV, SHG, and SHGT. The results further confirmed that signal losses on the network has a direct relationship with distance and also, vibration can as well help to normalize errors arising from poorly terminated cables and correct some splice faults as number of events an OTDR records are limited. This study also confirmed the possible use of this system to investigate underground movements likely to be earthquakes or road failure signs.
Dispersion Compensation Module for WDM -PON at 5 -GB/S Downstream with Variou...IRJET Journal
This document discusses dispersion compensation in wavelength division multiplexing passive optical networks (WDM-PONs) operating at 5 Gbps downstream transmission. It simulates various modulation formats, including duobinary, differential phase shift keying (DPSK), and on-off keying (OOK) to increase data speeds over different transmission distances. The combination of 87.5 km standard single mode fiber and 12.5 km dispersion compensating fiber is used to transmit over a total of 100 km while maintaining a low bit error rate and high Q factor. Dispersion compensation fibers are employed to counteract chromatic dispersion accumulated over long reaches of single mode fiber.
This document summarizes the design and testing of a 2.4 GHz microstrip patch antenna with a single slot for wireless local area network (WLAN) applications. The antenna was designed to improve the bandwidth and performance of conventional microstrip patch antennas. Simulation results showed a return loss of -37.5 dB and an impedance bandwidth of 2.3-2.6 GHz. Experimental testing agreed with simulations. The antenna achieved a gain of 5 dB and has applications in mobile communications, satellite communications, and wireless personal area networks due to its compact size, broadband capability, and high gain.
A 3-10 GHz Ultrawideband SiGe LNA with Wideband LC Matching NetworkRFIC-IUMA
Publicated in The International Society for Optical Engineering’s –
Microtechnologies for the New Millennium Design
(VLSI Circuits and Systems Conference),
Gran Canaria, España, 2007
In-band OSNR Monitoring Technique based on Brillouin Fiber Ring LaserDavid Dahan
We propose an improved technique for in-band OSNR monitoring based on a Brillouin fiber ring laser seeded by the optical channel to be monitored. This technique shows a reduction of the required input power into the monitor along with a large and tunable dynamic OSNR monitoring range. It is demonstrated experimentally and numerically for various bit rates and modulation formats
This document presents research on using a microstrip patch antenna as a sensor for electromagnetic interference (EMI) measurements. It describes how the antenna factor of the microstrip patch antenna was estimated through both simulations using CST Microwave Studio software and experimental measurements. The antenna factor relates the incident electric field to the received voltage and is an important parameter for EMI sensors. Simulation and experimental results showed good agreement for the estimated antenna factor versus frequency characteristics of the microstrip patch antenna, demonstrating its potential as an alternative EMI sensor.
The document discusses the use of optical fiber sensors for non-destructive testing applications. It notes that fiber optic sensors are well-suited for structural health monitoring due to their small size, light weight, and immunity to electromagnetic interference. The document outlines different types of fiber optic sensors and their advantages over conventional sensors. It also provides examples of how fiber optic sensors can be embedded in composite materials and structures to monitor factors like temperature, pressure, and strain for non-destructive testing.
The document outlines the contents of microwave and optical fiber lab experiments, including experiments measuring characteristics of devices like Gunn diodes, klystrons, and optical fibers as well as calibrating attenuators and measuring antenna patterns. It also provides descriptions of the components and functioning of an optical fiber trainer kit, including fiber preparation and characteristics of transmitters, receivers, and other devices used in optical communication experiments.
Transmission system used for optical fibers Jay Baria
In this presentation I have explained various types of transmission system used for optical transmission and also described about the budget method that has to be followed while selecting an source for optical fibers and also about the factors that should be consider while selecting an source.
Optical Fiber Communication Part 3 Optical Digital ReceiverMadhumita Tamhane
Current generated by photodetector is very weak and is adversely effected by random noises associated with photo detection process. When amplified, this signal further gets corrupted by amplifiers. Noise considerations are thus important in designing optical receivers.
Most meaningful criteria for measuring performance of a digital communication system is average error probability, and in analog system, it is peak signal to rms noise ratio. ...
Future Position X is a leading European cluster for innovative use of geographical information. It brings together research labs, markets, and networks to create new solutions for tomorrow's society and emerging markets. This drives growth through new services, products, companies, and jobs.
This document describes 5 experiments related to fiber optic communication:
1. Studied the relationship between an input analog signal and received signal over 650nm fiber. Signals remained the same.
2. Studied digital fiber link. Input square wave was transmitted and received successfully.
3. Studied intensity modulation using an analog input. Signal was modulated, transmitted, demodulated and amplified back to original.
4. Studied intensity modulation using a digital input. Signal was modulated and reconstructed at receiver.
5. Described a frequency modulation system. A 1kHz sine wave frequency modulated a digital signal, which was transmitted and demodulated to recover the original signal.
The document is an optical communication lab manual that outlines 8 experiments on optical fibers and fiber optic communication. Experiment 1 involves demonstrating different types of optical fibers and connectors. Experiment 2 establishes a 650nm fiber optic analog link. Experiment 3 establishes a 650nm digital fiber optic link. Experiment 4 studies intensity modulation using an analog input signal, transmitting it over fiber, and demodulating the output. Experiment 5 is similar but uses a digital input signal.
A directional coupler is used to combine and split optical signals. It consists of two input ports and two output ports. A 2x2 coupler splits the power from each input port between the two output ports. Star couplers combine multiple signals and broadcast them to many outputs. Isolators allow transmission in one direction but block transmission in the opposite direction, while circulators transmit signals between ports in a circular fashion. Multiplexers and demultiplexers combine and separate different wavelengths in WDM systems using interference filters such as arrayed waveguide gratings.
This presentation presents an overview of fiber optic sensor technology ,basic classifications of optic sensors, the basic functions of optical fiber sensors and also discusses the two important fiber optic sensors , namely the Mach - Zehnder interferometric fiber sensor and the fiber optic gyroscope.
A Bent, Shorted, Planar Monopole Antenna for 2.4 GHz WLAN ApplicationsSaou-Wen Su
A simple, bent monopole antenna well useful for WLAN applications in the 2.4 GHz band is presented. The monopole antenna has a rectangular radiating plate in general and is short-circuited to a small antenna ground and an assembly plate. The assembly plate is not only used as a supporting plate for antenna installation but also regarded as antenna ground. With a low profile of the monopole and use of the coaxial-line feed, the antenna has much flexibility in the placement inside a wireless device. Good radiation characteristics have been observed too.
This document discusses various optical components used in fiber optic communication systems. It describes passive components like couplers, isolators, filters, and multiplexers/demultiplexers. It also covers active components such as modulators, switches, optical amplifiers, and wavelength converters. Different technologies for implementing these components are presented, including micro-optics, integrated optics, fiber-based, and hybrid approaches. Key parameters and requirements for optical components are also outlined.
An Adaptive Energy Efficient Reliable Routing Protocol for Wireless Sensor Ne...IDES Editor
A reliable routing protocol for wireless sensor
networks (WSN) should be capable of adjusting to
constantly varying network conditions while conserving
maximum power. Existing Routing protocols provide
reliability at the cost of high energy consumption. In this
paper, we propose to develop an Adaptive Energy Efficient
Reliable Routing Protocol (AEERRP) with the aim of
keeping the energy consumption low while achieving high
reliability. In our proposed protocol, the data forwarding
probability is adaptively adjusted based on the measured
loss conditions at the sink. So only for high loss rates, a node
makes use of high transmission power to arrive at the sink.
Whenever the loss rate is low, it adaptively lessens the
transmission power. Since the source rebroadcasts the data,
until the packet loss is minimized, high data reliability is
achieved. By simulation results we show that the proposed
protocol achieves high reliability while ensuring low energy
consumption and overhead.
The document describes the development of a low-power portable laser spectroscopic sensor for atmospheric CO2 monitoring using tunable diode laser absorption spectroscopy, including the design of the sensor which is housed in an enclosure smaller than a shoebox, laboratory tests showing the sensor can accurately detect changing CO2 concentrations from soil and animal respiration, and field tests demonstrating the sensor's ability to measure forest floor respiration across a wireless sensor network.
(1) The document proposes an energy efficient protocol for wireless sensor networks (WSNs) that employs replicated data sinks to achieve resiliency against data sink failures and efficient storage and retrieval of sensor data.
(2) It introduces a simple address assignment scheme that partitions the sensor field into cells, with each cell containing one data sink and sensors closest to that sink. This scheme is scalable and resilient against data sink and sensor node failures.
(3) The protocol uses five types of messages and a routing approach based on de Bruijn digraphs to minimize energy consumption during data transmission between sensors and sinks. It aims to maximize the lifetime of the sensor network.
Eddy current displacement sensors are well-suited for measuring displacement, position, and gaps inside internal combustion engines under real operating conditions. Miniaturized eddy current sensors have been customized and installed at various engine locations, such as between the piston and cylinder wall, to measure thermal and mechanical stresses during normal running and motored operation. The non-contact sensors provide reliable data even in harsh engine environments with high temperature, pressure, vibrations, and contaminants.
The document discusses smart sensors and silicon technology. It defines smart sensors as sensors with integrated electronics that can perform logic functions, two-way communication, and make decisions. The document outlines the advantages of using silicon technology for smart sensors, such as reduced cost and size. It describes various types of silicon sensors that can measure physical and chemical variables like pressure, temperature, light, and chemicals. The document presents the general architecture of a smart sensor and discusses design considerations like signal conditioning, data conversion, and control processors. It provides examples of smart sensors developed for applications like infrared detection, acceleration measurement, and multisensing.
Accurate and Energy-Efficient Range-Free Localization for Mobile Sensor Networksambitlick
The document summarizes an algorithm called WMCL that improves the sampling efficiency and localization accuracy of existing SMC-based localization algorithms for mobile sensor networks. WMCL achieves higher sampling efficiency by further reducing the size of sensor nodes' bounding boxes, which restrict the scope from which candidate samples are selected, by up to 87%. This improves the sampling efficiency by up to 95%. WMCL also improves localization accuracy by using estimated position information from sensor neighbors, achieving similar accuracy with less communication and computation compared to other algorithms using similar methods.
Spread Spectrum Based Energy Efficient Wireless Sensor NetworksIDES Editor
The Wireless Sensor Networks (WSN) is
considered to be one of the most promising emerging
technologies. However one of the main constraints which
is holding back its wide range of applications is the
battery life of the sensor node and thus effecting the
network life. A new approach to this problem has been
presented in this paper. The proposed method is suitable
for event driven applications where the event occurrence
is very rare. The system uses spread spectrum as a means
of communication.
This document discusses a seminar presentation on smart sensors. It provides an introduction to smart sensors, defining them as sensors with integrated electronics that can perform logic functions, two-way communication, and make decisions. It discusses the usefulness of silicon technology in smart sensors and their general architecture. The architecture typically includes elements like a sensing element, amplifier, analog-to-digital converter, memory, and processor. In conclusions, smart sensors provide benefits like reduced costs, remote diagnostics, enhanced applications, improved reliability, and better signal-to-noise ratios compared to traditional sensors.
App152 en measurement-railroad-rails-laser-profile-sensorsISATECK
The document discusses using laser profile sensors to measure railroad rails to assess wear and prevent costly incidents from derailment. It describes mounting two synchronized scanCONTROL 2800 sensors under inspection cars traveling up to 100 km/h to quickly and accurately measure full rail profiles. The scanCONTROL 2800 sensors are the fastest and most precise available, meeting the demanding speed and accuracy needs for rail inspection.
This document is a project report submitted by four students for their Bachelor of Engineering degree. It examines quality of service improvement in wireless sensor networks. Specifically, it studies cluster-based routing protocols like LEACH and proposes modifications to LEACH called MODLEACH that introduces efficient cluster head replacement and dual transmitting power levels. Thresholding techniques are also incorporated into MODLEACH to further boost performance based on metrics like throughput, network lifetime and cluster head formations. The report analyzes and compares the performance of LEACH, MODLEACH, MODLEACH with hard thresholds and MODLEACH with soft thresholds through simulation and implementation in Qualnet and Matlab.
Focal Design Issues Affecting The Deployment Of Wireless Sensor Networks For ...Vinayak Kulkarni
This document discusses key design issues affecting the deployment of wireless sensor networks for pipeline monitoring. It identifies critical requirements such as the need for low-cost solutions to monitor long pipelines traversing remote areas. The document covers sensing modalities, power efficiency, energy harvesting, network reliability, and localization as major design categories. It emphasizes the need to consider these issues to facilitate effective pipeline monitoring using wireless sensor networks.
This document discusses cyclostationary feature detection for spectrum sensing in cognitive radio using various modulation schemes. It presents the block diagrams for cyclostationary feature detection without and with modulation. It simulates the detection using BPSK, QPSK, and 8-PSK modulation and analyzes the output cyclic spectral correlation function. The main results are that BPSK produces one primary and one secondary peak, QPSK produces one primary and two secondary peaks, and 8-PSK produces one primary and four secondary peaks in the output, allowing identification of the modulation scheme used.
Estimating Parameters of Multiple Heterogeneous Target Objects Using Composit...ambitlick
This article proposes a method for estimating parameters of multiple heterogeneous target objects (objects with different sizes and shapes) using networked binary sensors. The sensors are simple and only report detections, but no individual sensor location is known. The method introduces "composite sensor nodes" containing multiple sensors in a fixed arrangement. This provides relative location information to help distinguish individual target objects. As an example, the article considers a composite node with two sensors on a line segment. Measures from these nodes can identify target shapes and estimate object parameters like radius and side lengths. Numerical tests demonstrate networked composite sensors can estimate parameters of multiple target objects.
Prototyping a Wireless Sensor Node using FPGA for Mines Safety ApplicationIDES Editor
The sensor nodes in a wireless sensor network are
normally microcontroller based which are having limited
computational capability related to various applications. This
paper describes the selection, specification and realization of
a wireless sensor node using the field programmable gate
array (FPGA) based architecture for an early detection of
hazards (e.g fire and gas-leak ) in mines area. The FPGAs in
it’s place are more efficient for complex computations in
compare to microcontrollers, which is tested by implementing
the adaptive algorithm for removing the noise in sensor
received data in our work. Another advantage of using FPGA
is also due to it’s reconfigurable feature without changing
the hardware itself. The node is implemented using cyclone
II FPGA device present in Altera dE2 board .In this work the
network comprises of 4 nodes out of which 2 are test nodes,
one routing node and one base station node. An energy
efficient MAC protocol is tested for transmitting the data from
test node to base station node.
Wireless sensors for automation, monitoring, and control. 25+ year battery life - no battery replacement. Connect to any BAS network (BACnet, Modbus, LonWorks, more). The flexibility of wireless with the predictability and longevity of wired systems.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
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IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
1) The document discusses an improved self-cancellation scheme to reduce non-linearity in OFDM spectrum. It aims to optimize parallel cooperative sensing techniques to improve spectrum utilization.
2) It analyzes inter-carrier interference (ICI) caused by frequency offsets between transmitters and receivers in OFDM systems. ICI degrades performance but self-cancellation techniques can mitigate its effects.
3) The paper studies OFDM performance under frequency offsets in terms of carrier-to-interference ratio and bit error rate. Self-cancellation is shown to improve bit error rate compared to simple OFDM.
In-Depth Understanding of Fiber Optic Sensing NetworkSun Telecom
Fiber optic sensing network is a tendency for many applications. It supports a large number of sensors in a single optical fiber with high-speed, high security, and low attenuation. This article provides some information about fiber optic sensing networks.
This document summarizes and compares different spectrum sensing methods for cognitive radio networks. It discusses periodogram and multitaper methods (MTM) for power spectrum estimation. MTM addresses problems with periodogram like bias and variance. Receiver operating characteristic (ROC) curves are used to compare detection performance of different methods. MTM performance depends on number of tapers and time-bandwidth product. The paper evaluates MTM in terms of these and other parameters. It also provides background on cognitive radio, IEEE 802.22 networks, and the cognitive cycle of spectrum sensing, analysis and decision making. Experimental results comparing periodogram and MTM methods are presented.
This document summarizes research into improving the long-term temperature stability of a portable laser spectroscopic CO2 sensor. Tests were conducted in a temperature-controlled environment to identify temperature-sensitive components. Allan variance plots showed that temperature-induced drift was traced mostly to impacts on the laser's performance from variations in its heat-sink temperature. While the sensor demonstrated good short-term performance, a two-stage thermoelectric cooler for the laser could ameliorate long-term drift from temperature changes, though it would increase power consumption.
Laser-Based Standoff Methane Sensors for Enhancing Coal Miner SafetyClinton Smith
This presentation shows a demonstration of the PSI & Heath Consultants Remote Methane Leak Detector (RMLD) being applied to remote detection of methane within coal mines to supplement existing technology to further enhance coal miner safety.
Compact Hydrogen Peroxide Sensor for Sterilization Cycle MonitoringClinton Smith
Physical Sciences Inc. developed a compact hydrogen peroxide sensor using photoacoustic spectroscopy to monitor sterilization cycles. Strict limits on residual vapor phase hydrogen peroxide require detection down to 10 parts per billion, challenging with current technology. Through spectroscopic modeling and acoustic resonator optimization, the sensor achieves a detection limit of approximately 32 parts per billion of hydrogen peroxide in 10,000 parts per million of water vapor interference. Experimental results validate the sensor performance compared to an industry standard. The low-cost, field-deployable sensor will aid pharmaceutical manufacturing in ensuring sterile conditions.
High-accuracy laser spectrometers for wireless trace-gas sensor networksClinton Smith
The document outlines Clinton J. Smith's final public oral exam for his dissertation on developing laser spectrometers for wireless trace gas sensor networks. The dissertation aims to develop CO2 sensors for deployment in a real-time sensor network to monitor carbon fluxes over a broad area. The outline includes development of a wireless laser spectroscopic sensor node for atmospheric CO2 monitoring, quantifying and improving the accuracy of wireless sensor network nodes, developing a solar-powered distributed wireless CO2 monitoring network, techniques for real-time calibration, and conclusions. Laboratory and field tests show the sensors can accurately measure CO2 concentrations with precision below 1% and linear response over large concentration ranges.
A rotational reference cell for high-accuracy real-time spectroscopic trace-g...Clinton Smith
This document summarizes a technique for real-time calibration of portable trace-gas sensors using a rotating in-line gas cell. Key challenges addressed are measurement drift over time from factors like optical instability. Traditional calibration methods lack portability or require separate reference cells. The presented method uses a single gas cell with three sub-cells that rotate between a reference gas, sample gas, and empty cell. Dividing the sample and reference signals by the empty background cell suppresses parasitic interference fringes. Spectral correlation of reference and sample signals over time provides real-time calibration and improved precision without needing wavelength calibration. Future work aims to address detector non-linearity and minimize background signals for field deployment of the calibration technique.
Inline Reference Cell for Reatime Calibration of Laser Absorption SpectrometersClinton Smith
The document discusses developing a technique for real-time calibration of portable trace-gas sensors using an in-line reference cell. It aims to differentiate between sample and reference signals based on physical parameters of the gas and wavelength modulation spectroscopy modeling. Key challenges addressed are reducing measurement drift over time. The proposed method inserts a permanent low-pressure reference cell to experience the same optical effects as the sample. Simulations and experiments show this approach can minimize cross-talk between sample and reference signals depending on parameters like pressure, modulation depth, and harmonic detection order.
This document discusses using a vertical-cavity surface-emitting laser (VCSEL) as an optical clock source for atomic clocks. It aims to create a more power efficient and compact atomic clock by replacing microwave components with a self-oscillating VCSEL. The VCSEL's polarization self-switching property allows it to act as an oscillator. Changing the VCSEL's drive current can tune the self-oscillation frequency by altering the cavity phase, as represented by the heterodyne beatnote between orthogonal polarization modes. Rotating a quarter wave plate in the external cavity feedback loop can also tune the frequency. Calculations match experiments showing frequency tuning from varying the birefringence and quarter wave plate offset angle.
Low-power Portable Laser Spectroscopic Sensor for Atmospheric CO2 MonitoringClinton Smith
This document summarizes the development of a portable, low-power laser spectroscopic sensor for atmospheric CO2 monitoring. Key points:
- The sensor uses tunable diode laser absorption spectroscopy (TDLAS) inside a protective enclosure to measure CO2 concentrations with high sensitivity, selectivity, and stability.
- Lab tests show the sensor can detect CO2 concentrations with 0.113 ppm sensitivity and 5.1x10-7 ultimate minimum detectable absorption. Field tests compare well to commercial sensors.
- Future work will improve thermal stability and develop an open path design and sensor network for broad-scale carbon flux monitoring.
CLEO 2009: High Frequency Polarization Switching VCSEL Clock Using Subwavelength Quarter-Wave Plate
by:
Clinton J. Smith, Wen-Di Li, Shufeng Bai, and Stephen Y. Chou
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
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A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
1. Low-power Wireless Trace Gas
Sensing Network
Clinton J. Smith,1 Stephen So,1 Amir Khan,2 Mark A. Zondlo2, and Gerard Wysocki1
1 – Dept. of Electrical Engineering, Princeton University, Princeton, NJ 08544
2 – Dept. of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544
Motivation Sensor Node Configuration Proof-of-concept Sensor Network
The CO2 impact on the greenhouse gas effect requires global and local Sensor Head
VCSEL
monitoring capability which would greatly benefit from availability of sensors CO2 Environment Base
0.5m
that are lightweight, portable, robust, highly sensitive, and selective. Station 3.3m
TEC Detector
For study of the Carbon Cycle, these sensors should also be low- Multi-pass Cell
FL Sensor
CW Power
power/battery operated and capable of being wirelessly networked and Supply
autonomous. Temperature GL Sensor
Control Amplifiers
Large area wireless networks of laser-based trace-gas sensors will provide Function
Generator
high spatial resolution of real time concentration data with unprecedented Signal
Lock-In
sensitivity and selectivity to the target molecular species. Processing
These sensors are expected to maintain a high degree of long-term stability
Computer
in the field, despite changing environmental conditions.
A schematic of the optical configuration and a block diagram of the electrical control
systems. For the long term stability test the sensor head (indicated above) was placed
in a temperature controlled chamber.
Background Sensor Node Long-term Performance A basic network consisting of two sensor nodes and a base
We have built a laser spectroscopic sensor for CO2 detection and station has been setup in a laboratory
demonstrated its performance in preliminary laboratory and field The network has been operated for 8 hours continuously
tests [1]. acquiring CO2 concentration data
These tests revealed a temperature induced drift affecting the Laboratory activity can be interpreted from this data set.
The high concentration events near 0 hours as shown by the FL
long term performance of the sensor. Sensor are caused by the operator working at the base station to
We studied and identified the temperature sensitive components configure the WSN.
by performing tests in a well-controlled environment. The baseline reflects the overall activity in the room while the
To demonstrate wireless sensor network (WSN) capability a two- high short-time concentration spikes refer to individuals
working in the vicinity of the sensor.
node network similar to [2] for long-term real-time monitoring of
Both at the beginning (hour 0) and at the end (hour 8) the CO2
CO2 has been investigated. concentration exhibits a low baseline level corresponding to low
human activity in the lab.
Summary and Future Directions
CO2 sensor-node. The While our portable CO2 laser spectroscopic sensor has
total size is less than shown excellent short term performance [1], it also has
that of a shoebox. evident temperature induced stability issues over long
time.
We have demonstrated a proof-of-concept two sensor-
node network for long-term real-time CO2 concentration
CO2 concentration time series show the degree to which temperature monitoring.
References:
[1] C. J. Smith, S. So, and G. Wysocki, "Low-Power Portable Laser Spectroscopic Sensor for Atmospheric stabilization improves sensor-node performance. Allan deviation Future directions:
CO2Monitoring," in Conference on Laser Electro-Optics: Applications, OSA Technical Digest (CD) (Optical
Society of America, 2010), paper JThB4.
calculation of long term concentration measurements allows Currently we are developing a real-time calibration
[2] S. So, A. A. Sani, Z. Lin, F. Tittel, and G. Wysocki, "Demo abstract: Laser-based trace-gas chemical quantifying the sensor stability. Sensor performance outside the method as the most reliable solution for sensor drift
sensors for distributed wireless sensor networks," in Information Processing in Sensor Networks, 2009.
IPSN 2009. International Conference on(2009), pp. 427-428. temperature controlled chamber experiences slow drift. Inside the problems.
This material is based upon work supported by the National Science Foundation temperature controlled environment, the drift is largely eliminated. A large area WSN will be deployed in the field for long-
under Grant No. EEC-0540832, an NSF MRI award #0723190 for the openPHOTONS systems and
National Science Foundation Grant No. 0903661 “Nanotechnology for Clean Energy IGERT.” term trace-gas monitoring.