The document discusses fast factorized back projection (FFBP) for processing circular synthetic aperture radar (CSAR) data. FFBP divides the synthetic aperture into sub-apertures and backprojects them onto polar grids. For CSAR, the polar grids for each sub-aperture must change orientation to follow the circular trajectory. Experimental results using real CSAR data from Germany's E-SAR system show FFBP adapted for CSAR provides high-accuracy reconstruction and is over 25,000 times faster than conventional backprojection.
In the modern age, High-resolution radar images can be achieved by employing SAR technique. It is well
known that SAR can provide several times better image resolution than conventional radars. The exploration for efficient
image denoising methods still remains a valid challenge for researchers. Despite the difficulty of the recently proposed
methods, mostly of the algorithms have not yet attained a pleasing level of applicability; each algorithm has its
assumptions, advantages, and limitations. This paper presents a review of synthetic aperture radar. Behind a brief
introduction in our work we are especially targeting the noise called backscattered noise in SAR terminology which
causes the appearance of speckle Potential future work in the area of air flight navigation, mapping Weather Monitoring
& during natural disaster like earth quake. The SAR having the capability, to make human visibility beyond optical
vision, is also discussed.
Presentation made by Prof. Adriano Camps (Universitat PolitĂšcnica de Catalunya) at ICMARS 2010 (India, 16-December-2010) on the MIRAS instrument aboard ESA's SMOS mission.
In the modern age, High-resolution radar images can be achieved by employing SAR technique. It is well
known that SAR can provide several times better image resolution than conventional radars. The exploration for efficient
image denoising methods still remains a valid challenge for researchers. Despite the difficulty of the recently proposed
methods, mostly of the algorithms have not yet attained a pleasing level of applicability; each algorithm has its
assumptions, advantages, and limitations. This paper presents a review of synthetic aperture radar. Behind a brief
introduction in our work we are especially targeting the noise called backscattered noise in SAR terminology which
causes the appearance of speckle Potential future work in the area of air flight navigation, mapping Weather Monitoring
& during natural disaster like earth quake. The SAR having the capability, to make human visibility beyond optical
vision, is also discussed.
Presentation made by Prof. Adriano Camps (Universitat PolitĂšcnica de Catalunya) at ICMARS 2010 (India, 16-December-2010) on the MIRAS instrument aboard ESA's SMOS mission.
SAR is a type of radar which works with antenna and receiver using radio waves which can create two dimension or three dimension of the objects . A synthetic-aperture radar is an imaging radar mounted on a moving platform. SAR gives high resolution data and works 24*7.
AESA Airborne Radar Theory and Operations Technical Training Course SamplerJim Jenkins
Â
The revolutionary active electronically scanned array (AESA) Radar provides huge gains in performance and all the front line fighters in the world from the Americans (F35, F22, F18, F15, F16) to the Europeans, Russians and Chinese already have one or soon will. This four day seminar, which took 10,000 man hours to produce, is a comprehensive treatment on the latest systems engineering technology required to design the modes for an AESA to capitalize on the systems inherent multi role, wide bandwidth, fast beam switching, and high power capabilities. Steve Jobs once said âYou must provide the tools to let people become their bestâ, and this seminar will include two indispensable tools for the AESA engineer. 1) A newly written 400+ page electronic book with interactive calculations and simulations on the more complicated seminar subjects like STAP and Automatic Target Recognition. 2) A professionally designed spread sheet (with software) for designing, capturing and predicting the detection performance of the AESA modes including the challenging Alert-Confirm waveform.
Explanation of very simple methods for atmospheric corrections and an example adapted from a paper of the Dept. of Thermodynamics, University of Valencia, Spain.
Conferencia impartida por SebastiĂĄn SĂĄnchez en los Viernes CientĂficos organizada por la Facultad de Ciencias Experimentales de la Universidad de AlmerĂa el 14 de enero de 2011.
SAR is a type of radar which works with antenna and receiver using radio waves which can create two dimension or three dimension of the objects . A synthetic-aperture radar is an imaging radar mounted on a moving platform. SAR gives high resolution data and works 24*7.
AESA Airborne Radar Theory and Operations Technical Training Course SamplerJim Jenkins
Â
The revolutionary active electronically scanned array (AESA) Radar provides huge gains in performance and all the front line fighters in the world from the Americans (F35, F22, F18, F15, F16) to the Europeans, Russians and Chinese already have one or soon will. This four day seminar, which took 10,000 man hours to produce, is a comprehensive treatment on the latest systems engineering technology required to design the modes for an AESA to capitalize on the systems inherent multi role, wide bandwidth, fast beam switching, and high power capabilities. Steve Jobs once said âYou must provide the tools to let people become their bestâ, and this seminar will include two indispensable tools for the AESA engineer. 1) A newly written 400+ page electronic book with interactive calculations and simulations on the more complicated seminar subjects like STAP and Automatic Target Recognition. 2) A professionally designed spread sheet (with software) for designing, capturing and predicting the detection performance of the AESA modes including the challenging Alert-Confirm waveform.
Explanation of very simple methods for atmospheric corrections and an example adapted from a paper of the Dept. of Thermodynamics, University of Valencia, Spain.
Conferencia impartida por SebastiĂĄn SĂĄnchez en los Viernes CientĂficos organizada por la Facultad de Ciencias Experimentales de la Universidad de AlmerĂa el 14 de enero de 2011.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Development of triangular array eight patches antennas for circularly-polariz...TELKOMNIKA JOURNAL
Â
In this paper, we obtain the left-handed circularly polarized (LHCP) and right-handed circularly polarized (RHCP) of triangular array eight patches antennas using corporate feeding-line for circularly polarized-synthetic aperture radar (CP-SAR) sensor embedded on unmanned aerial vehicle (UAV) with compact, simple, and efficient configuration. Although the corporate feeding-line design has already been developed, its design was for the side antenna view of 0° and only produced one of LHCP or RHCP instead of both. Here, the design for LHCP and RHCP eight patches array fed by corporate feeding-line having the side antenna view of 36° at f=1.25 GHz for CP-SAR are discussed. We use the 2016 version of computer simulation technology (CST) to realize the method of moments (MoM) for analyzing. The performance results, especially for gain and axial ratio (Ar) at resonant frequency are consecutively 13.46 dBic and 1.99 dB both of LHCP and RHCP. Moreover, the 12-dBic gain-bandwidth and the 3-dB Ar-bandwidth of them are consecutively around 38 MHz (3.04%) and 6 MHz (0.48%). Furthermore, the two-beams appeared at boresight in elevation plane for average beamwidth of 12 dBic-gain and the 3 dB-Ar LHCP and RHCP have similar values of around 12° and 46°, respectively.
This content presents for basic of Synthetic Aperture Radar (SAR) including its geometry, how the image is created, essential parameters, interpretation, SAR sensor specification, and advantages and disadvantages.
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
Â
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
Â
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
Â
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
Â
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
Â
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties â USA
Expansion of bot farms â how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks â Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Â
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as âpredictable inferenceâ.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
Â
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. Whatâs changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Â
Clients donât know what they donât know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clientsâ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Â
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
DevOps and Testing slides at DASA ConnectKari Kakkonen
Â
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Â
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...
Â
IGARSS11_FFBP_CSAR_v3.ppt
1. Octavio Ponce, Pau Prats , Marc Rodriguez-Cassola, Rolf Scheiber, Andreas Reigber Microwave and Radar Institute (HR) German Aerospace Center Processing of Circular SAR Trajectories with Fast Factorized Back-Projection
22. FFBP CSAR - Simulation . 700m Terrain 4000m Height 4500m Radius 94MHz BW L Band 400Hz PRF
23. FFBP CSAR - Simulation *Interpolator ï Knab Pulse of 21 points BP vs FFBP Knab, IEEE TIT, 1979
24. FFBP CSAR - Performance Speed Up System, Geometry, Hardware, Interpolator BP CPU ïš ~238days 25000 x 25000 pixels ~3 hrs FFBP GPU ~11 hrs FFBP CPU ~3 days BP GPU Speed up factor
Circular SAR mode is the acquisition of data of a spotlighted target region over 360° synthetic aperture. This geometry depends mainly on the platform height, flight radius, and aperture angle.
One of the biggest potential of CSAR is its resolution, because it can be smaller than the wavelength. Here we can see a simulated Impulse response of Stripmap SAR mode, which is basically a 2d sinc. Its resolution depends on the spectrum bandwidth in range and azimuth direction.
On the other hand, the resolution in CircularSAR depends mainly on the diameter of the ring, that means much more resolution than stripmap in both dimensions. The thickness of this ring is the bandwidth of the system. The ring has the same shape as the flight track. In time domain the 2d IR is the difference of 2 bessel functions.
The highest resolution in ground range is defined as lambda over four depending on the depression angle. In this case for L-Band the highest resolution would be 8cm, this allows a reduction in the speckle as weâll see later. In a typical case of Stripmap weâll get 1.5m x 1.m, with the same system but different geometry we can get higher resolution.
CSAR has also potential to get reconstruction in 3D. Computer aided Tomography. Conventional SAR cannot overcome altitude ambiguity caused by two such scattering centers that lie along a common wavefront but at different altitudes. The system geometry resolves height ambiguities by obtaining measurements made from different azimuthal angles along the flight track.
This is a 3D IRF of CSAR with one pass focused from -5 to 15m. We can see that at the true height we get a peak with the maximum energy. At the wrong height weâll get a a ring as a result, which increases its size as we increase the distance from the true height.
The problem that we were leading with, was the development of a focusing algorithm, that was efficient in time (low computational burden), using the real track to avoid approximations, considering the topography changes, getting high accuracy in amplitude and phase.
FFBP, based on the Direct BP,and it was first developed for the spotlight mode, it solves the problem of the computational burden by splitting the full synthetic aperture of L pulses into smaller subapertures of Lm pulses, focusing several coarse images with the direct back projection but in polar coordinates. Afterwards each two contiguous images are merged by a polar interpolation, in this way increasing the resolution in the direction of the flight, until we reach the full synthetic aperture. At this point we can perform an interpolation from a polar to a Cartesian grid.
Why is it done in polar coordinates? Because the sampling conditions are much better than in Cartesian coordinates, as shown in this images. This fact helps also to decrease the computational burden.
If we focused two images, q1a and q2a, which we would like to interpolate into q1b. Our knowns are a_1b and r_1b, we now the distance of each subaperture center d_d. Then by the law of cosines we can get a_1a and a_r1a
This is a graphic example.
This is a graphic example.
How do we perform the P2P interpolation? If we have focused an image with respect to q1a, which we want to interpolate to the new reference system q1b, we canât use the law of cosines as defined for stripmap because we donâT want the angle with respect to the distance vector between the two subaperture centers. Instead we would like to get the angle with respect to the vector q1a, as we define our system. To solve this we have to project the known coordinates a_1b and r_1b to the ground, using the DEM and followed by a rotation of b_deg and a translation with respect to q1b. In that way weâll get the distance r_1a and a_1a by means of the dot product of two vectors. Now we start interpolating two by two contiguous imagesâŠ..
Now the full resolution final grid of ~lambda over 4 weâll be used until we reach Lmax pulses. In this case 45°, and we need to interpolate only 8 times using the full resolution grid. Simple and fast solution.
We did a simulation of a circular flight withâŠâŠ
To measure the performance we use as a reference the direct BP. The results with simulated data indicateâŠâŠ high accuracy in amplitude and phase. For this the truncated-sinc + knab pulse of 21 points was used.
Direct BP and FFBP was also parallelized on a GPU, in order to accelerate even more the process. Here we see the speed up factor of DBP and FFBP with respect to the dBP tested on the CPU. The dBP with the GPU (black line) was 100times faster, while the FFBP CPU (red line) shows an improvement of 500, but this is not all, the FFBP GPU improves this factor up to 1800. As an example, we took a matrix size of 25kx25k pixels (1.5x15km, 6cm res), the BP CPU lasts 238days, while BP GPU took 3 days, FFBP CPU was improved to 11 hours and with the GPU to 3 hours. This results depend directly on the PRF, RADIUS, HARDWARE & INTERPOLATOR
We analyzed the real data acquired in a campaign with the ESAR system in Kaufbeuren GermanyâŠ..
The results comparing the BP with the FFBP indicateâŠâŠ high accuracy in amplitude and phase.
The results comparing the BP with the FFBP indicateâŠâŠ high accuracy in amplitude and phase.
This animation shows images that were focused in subapertures of 10° over the 360° full synthetic aperture. Polarimetric signature changes as a function of the aspect angleâŠ.. Smearing objects are moving targets. Resonance (flash fields) Saturation because of the high energy backscattered
Lights on the Runway No speckle More resolution
It is possible to see through the cannopy Tree Trunks as double bounce Shape of the buildings Fence as double bounce
Defocused soil Luneberg lens as double bounce Importance of the DEM Inaccuracies of the DEM can be corrected with CSAR Ring effect as shown at the beginning
3D IRF as shown in the first slides!
Tree trunk (Double bounce) focused at Height = 0m
In this way the measured signal in fast-time and slow-time (t,phi), can be described by the convolution of the reflectivity function f(x,y,z) and the transmitted radar signal P(t).
In the left image itâs possible to see an overview of the circular trajectory and next to it the beam pattern of the L-Band antenna during the flight. Common illuminated Spot
This is a sequence of P2P interpolations correspondent from 1 to 45 degrees. We can see that the spectrum starts to curve as we increase the size of the subaperture. This causes an increment in number of samples in range direction, to avoid aliasing. Therefore it is not worth to keep interpolating in polar grids, and an interpolation to final cartesian grid should be done before we reach the FullSA. This fact doesnât overcome the great improvement in terms of computational burden, since large blocks of data can be processed and only few times the full resolution in cartesian grid is used. Interpolation Kernel.
For every Polar to polar interpolation the grids should be calculated.