scholarly journals Motion compensation of short-range, wide-beam synthetic aperture radar

2011 ◽  
Vol 9 ◽  
pp. 61-66
Author(s):  
T. Reichthalhammer ◽  
E. Biebl
Keyword(s):  
Image Reconstruction ◽  
Motion Compensation ◽  
Short Range ◽  
Processing Time ◽  
Synthetic Aperture ◽  
Phase Reconstruction ◽  
Worst Case ◽  
Wide Beam ◽  
Detection Systems ◽  
Very High

Abstract. Up to now, SAR systems are a well known possibility for long-range detection. Applying them for short-range applications with wide-beam antennas, of course, does not increase the resolution but the probability to detect hidden targets with an anisotropic radar cross section significantly in comparison to other detection systems. Working with an appropriate wavelength even improves the possiblity to look through natural cover like grass. An application is detecting fawn while pasture mowing. The main issue in such applications is the antenna's motion in range direction as it is carried by cars or traction engines. If motion is not compensated, the phase cannot be reconstructed correctly, the resolution gets poorer and, in worst case, the target even disappears. Conventional methods for motion compensation either fail for wide beam antennas, since for contributions of wide angles the phase reconstruction is incorrect, or is not applicable for realtime data processing, because the processing time due to interpolation or similar steps is very high. We present a method of image reconstruction regarding motion of the antenna as well as wide beamwidth. This method is analyzed concerning processing time in comparison to the conventional image reconstruction. In our system we use a combination of algorithms. There is shown a comparison for different algorithms dependent of the antenna's motion and aperture angle.

Cost Effective Swath Bathymetry

2001 ◽  
Vol 35 (4) ◽  
pp. 33-45 ◽  
Author(s):  
Peter Hogarth
Keyword(s):  
Processing Time ◽  
Cost Effective ◽  
High Accuracy ◽  
High Coverage ◽  
Swath Bathymetry ◽  
World Survey ◽  
Set Up ◽  
Very High ◽  
Harbor Area ◽  
Wide Swath

Between 23rd and 25th July 2001 GeoSwath, a high specification shallow water wide swath bathymetry system, was used to survey the entire Portsmouth NH Harbor area. This paper deals with the results of this survey, illustrating the potential for significant reductions in the high costs, which have prevented widespread proliferation of Swath Bathymetry systems to date. Data, including a complete DTM gridded to 1 m resolution, will be presented and discussed in detail. These results show that the system is very easy to set up and use, requires greatly reduced boat and processing time, whilst offering high accuracy and very high coverage and resolution when used in a real-world survey of a dynamic harbor environment.

scholarly journals The InflateSAR Campaign: Testing SAR Vessel Detection Systems for Refugee Rubber Inflatables

2021 ◽  
Vol 13 (8) ◽  
pp. 1487
Author(s):  
Peter Lanz ◽  
Armando Marino ◽  
Thomas Brinkhoff ◽  
Frank Köster ◽  
Matthias Möller
Keyword(s):  
Water Surface ◽  
Operating Characteristic ◽  
Incidence Angle ◽  
Roc Curves ◽  
Synthetic Aperture ◽  
Moving Window ◽  
Threshold Selection ◽  
Detection Systems ◽  
Experimental Campaign ◽  
X Band

Countless numbers of people lost their lives at Europe’s southern borders in recent years in the attempt to cross to Europe in small rubber inflatables. This work examines satellite-based approaches to build up future systems that can automatically detect those boats. We compare the performance of several automatic vessel detectors using real synthetic aperture radar (SAR) data from X-band and C-band sensors on TerraSAR-X and Sentinel-1. The data was collected in an experimental campaign where an empty boat lies on a lake’s surface to analyse the influence of main sensor parameters (incidence angle, polarization mode, spatial resolution) on the detectability of our inflatable. All detectors are implemented with a moving window and use local clutter statistics from the adjacent water surface. Among tested detectors are well-known intensity-based (CA-CFAR), sublook-based (sublook correlation) and polarimetric-based (PWF, PMF, PNF, entropy, symmetry and iDPolRAD) approaches. Additionally, we introduced a new version of the volume detecting iDPolRAD aimed at detecting surface anomalies and compare two approaches to combine the volume and the surface in one algorithm, producing two new highly performing detectors. The results are compared with receiver operating characteristic (ROC) curves, enabling us to compare detectors independently of threshold selection.

scholarly journals Effects of Motion Compensation Residual Error and Polarization Distortion on UAV-Borne PolInSAR

2021 ◽  
Vol 13 (4) ◽  
pp. 618
Author(s):  
Zexin Lv ◽  
Fangfang Li ◽  
Xiaolan Qiu ◽  
Chibiao Ding
Keyword(s):  
Motion Compensation ◽  
Residual Error ◽  
Synthetic Aperture ◽  
Interferometric Synthetic Aperture Radar ◽  
Practical Application ◽  
Aerial Vehicle ◽  
Application Potential ◽  
Large Motion ◽  
Simulation Results ◽  
Interferometric Sar

Polarimetric Interferometric Synthetic Aperture Radar (PolInSAR) can improve interferometric coherence and phase quality, which has good application potential. With the development of the Mini-SAR system, Unmanned Aerial Vehicle borne (UAV-borne) PolInSAR systems became a reality. However, UAV-borne PolInSAR is easily affected by air currents and other factors, which may cause large motion errors and polarization distortion inevitably exists. However, there are few pieces of research which are about motion compensation residual error (MCRE) and polarization distortion effects on PolInSAR. Though the effects of MCRE on Interferometric SAR (InSAR) and polarization distortion on PolInSAR were studied, respectively, these two parts are independently modeled and analyzed. In this paper, a model that simultaneously considers the effects of these two kinds of errors is proposed, and simulation results are given to validate the model. Then, a quantitative analysis based on a real Quadcopter UAV PolInSAR system is performed according to the model, which is valuable for system design and practical application of the UAV-borne PolInSAR system.

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