Simulated images of urban areas using an extended GTD ray-tracing model of the synthetic aperture radar

1995 ◽  
Author(s):  
Shahram Tajbakhsh ◽  
Min-Joon Kim ◽  
H. M. Berenyi ◽  
Ronald E. Burge
Keyword(s):  
Synthetic Aperture Radar ◽  
Ray Tracing ◽  
Urban Areas ◽  
Synthetic Aperture ◽  
Simulated Images ◽  
Ray Tracing Model ◽  
Aperture Radar

Color Coding of Synthetic Aperture Radar Imagery

1984 ◽  
Vol 28 (4) ◽  
pp. 303-307
Author(s):  
Frank Ward ◽  
Denise Wilson ◽  
Donald Wallquist ◽  
Gilbert Kuperman
Keyword(s):  
Synthetic Aperture Radar ◽  
Transmission Lines ◽  
Urban Areas ◽  
Power Transmission ◽  
Synthetic Aperture ◽  
Power Transmission Lines ◽  
Oil Refineries ◽  
Black And White ◽  
Sar Imagery ◽  
Aperture Radar

The purpose of our study was to investigate four types of coding strategies using the same Synthetic Aperture Radar (SAR) imagery. We digitized unclassified SAR imagery to include scenes from urban areas, seaports, oil refineries, industrial sites, an airfield, and power transmission lines. Two color and two black and white (BW) coding schemes were applied to the imagery. Five experienced radar interpreters were briefed and viewed 35 mm slides of the imagery. They judged image usefulness by reference to an interpretability scale. Analysis of the ratings showed that the BW codes received significantly higher interpretability ratings than the color codes.

scholarly journals Robust algorithm for detecting floodwater in urban areas using synthetic aperture radar images

2018 ◽  
Vol 12 (04) ◽  
pp. 1 ◽  
Author(s):  
David C. Mason ◽  
Sarah L. Dance ◽  
Sanita Vetra-Carvalho ◽  
Hannah L. Cloke
Keyword(s):  
Synthetic Aperture Radar ◽  
Urban Areas ◽  
Synthetic Aperture ◽  
Robust Algorithm ◽  
Radar Images ◽  
Aperture Radar

scholarly journals TOWARDS A SEMANTIC INTERPRETATION OF URBAN AREAS WITH AIRBORNE SYNTHETIC APERTURE RADAR TOMOGRAPHY

2016 ◽  
Vol III-7 ◽  
pp. 235-242 ◽  
Author(s):  
O. D'Hondt ◽  
S. Guillaso ◽  
O. Hellwich
Keyword(s):  
Synthetic Aperture Radar ◽  
Urban Areas ◽  
Point Cloud ◽  
Semantic Interpretation ◽  
Synthetic Aperture ◽  
Classification Rules ◽  
Building Facades ◽  
The City ◽  
Geometric Primitives ◽  
Aperture Radar

In this paper, we introduce a method to detect and reconstruct building parts from tomographic Synthetic Aperture Radar (SAR) airborne data. Our approach extends recent works in two ways: first, the radiometric information is used to guide the extraction of geometric primitives. Second, building facades and roofs are extracted thanks to geometric classification rules. We demonstrate our method on a 3 image L-Band airborne dataset over the city of Dresden, Germany. Experiments show how our technique allows to use the complementarity between the radiometric image and the tomographic point cloud to extract buildings parts in challenging situations.

scholarly journals Evaluation of Coherent and Incoherent Landslide Detection Methods Based on Synthetic Aperture Radar for Rapid Response: A Case Study for the 2018 Hokkaido Landslides

2020 ◽  
Vol 12 (2) ◽  
pp. 265 ◽  
Author(s):  
Jungkyo Jung ◽  
Sang-Ho Yun
Keyword(s):  
Synthetic Aperture Radar ◽  
Urban Areas ◽  
Rapid Response ◽  
Synthetic Aperture ◽  
Detection Methods ◽  
Intensity Correlation ◽  
Low Coherence ◽  
Multi Temporal ◽  
Log Ratio ◽  
Aperture Radar

Damage mapping using Synthetic Aperture Radar (SAR) imagery has been studied in recent decades to support rapid response to natural disasters. Many researches have been developing coherent and incoherent change detection. However, their performances can vary depending on the types of the damages, the characteristics of the scatterers and the corresponding capability of algorithms. In particular, the coherence-based methods have been used as promising detectors over urban areas where high coherences are observed, but their detection accuracies still remain controversial over the area where low coherences are mainly observed such as the 2018 Hokkaido landslides. In order to understand the characteristics of landslide (damage) detectors for low-coherence areas and find an alternative and complementary method, we designed the coherence difference, coherence normalized difference, log-ratio, intensity correlation difference, and normalized differences of the intensity correlation assuming limited availability of dataset, and also developed multi-temporal algorithms using the coherence, intensity, and intensity correlation. They were tested and evaluated using multiple polygons extracted from aerial photos. We were able to observe that the multi-temporal intensity correlation method has the potential to detect the landslides over the low coherence region and all types of land uses.

scholarly journals The Combined Effect of Orientation Angle and Material on PolSAR Images of Urban Areas

2020 ◽  
Vol 12 (10) ◽  
pp. 1632
Author(s):  
Laetitia Thirion-Lefevre ◽  
Régis Guinvarc’h ◽  
Elise Colin-Koeniguer
Keyword(s):  
Synthetic Aperture Radar ◽  
Urban Areas ◽  
Orientation Angle ◽  
Combined Effect ◽  
Synthetic Aperture ◽  
Polarimetric Synthetic Aperture Radar ◽  
A Value ◽  
Important Impact ◽  
Aperture Radar

Polarimetric Synthetic Aperture Radar (PolSAR) images containing cities may exhibit misclassified areas when using polarimetric decompositions. Several articles relate this problem to the effects of orientation between the facades of buildings and the acquisition trajectory. Materials also play a role in polarimetric behavior. This paper deals with this combined effect of material and orientation. It analyzes different sets of data, airborne or space-borne, at L-, C- and X-bands, and for different orientation angles. It shows that considering dielectric dihedral rather than metallic in the polarimetric mechanism of double-bounce has a very important impact on the differences of intensities between the channels HH and VV. This difference is very important for small angles of orientation, and then decreases for large angles. Furthermore, the curves of the ratios between polarimetric intensities as a function of the orientation angle vary little with the materials and the frequencies encountered in all the scenarios envisaged. The signal of the ratio VV/HH raises a plateau around −1 dB for orientations higher than 30°. We also observe a plateau for HV/HH, but with a value around −5 dB.

Images of urban areas by a synthetic aperture radar simulator

1994 ◽  
Author(s):  
Shahram Tajbakhsh ◽  
Min-Joon Kim ◽  
H. M. Berenyi ◽  
Ronald E. Burge
Keyword(s):  
Synthetic Aperture Radar ◽  
Urban Areas ◽  
Synthetic Aperture ◽  
Radar Simulator ◽  
Aperture Radar

scholarly journals Study of the Effects of Target Geometry on Synthetic Aperture Radar Images using Simulation Studies

2014 ◽  
Vol XL-8 ◽  
pp. 1227-1231
Author(s):  
K. Tummala ◽  
A. K. Jha ◽  
S. Kumar
Keyword(s):  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
Target Area ◽  
Simulation Algorithm ◽  
Sar Image ◽  
Sar Images ◽  
Radar Images ◽  
The Earth ◽  
Simulated Images ◽  
Aperture Radar

Synthetic aperture radar technology has revolutionized earth observation with very high resolutions of below 5m, making it possible to distinguish individual urban features like buildings and even cars on the surface of the earth. But, the difficulty in interpretation of these images has hindered their use. The geometry of target objects and their orientation with respect to the SAR sensor contribute enormously to unexpected signatures on SAR images. Geometry of objects can cause single, double or multiple reflections which, in turn, affect the brightness value on the SAR images. Occlusions, shadow and layover effects are present in the SAR images as a result of orientation of target objects with respect to the incident microwaves. Simulation of SAR images is the best and easiest way to study and understand the anomalies. This paper discusses synthetic aperture radar image simulation, with the study of effect of target geometry as the main aim. Simulation algorithm has been developed in the time domain to provide greater modularity and to increase the ease of implementation. This algorithm takes into account the sensor and target characteristics, their locations with respect to the earth, 3-dimensional model of the target, sensor velocity, and SAR parameters. two methods have been discussed to obtain position and velocity vectors of SAR sensor – the first, from the metadata of real SAR image used to verify the simulation algorithm, and the second, from satellite orbital parameters. Using these inputs, the SAR image coordinates and backscatter coefficients for each point on the target are calculated. The backscatter coefficients at target points are calculated based on the local incidence angles using Muhleman's backscatter model. The present algorithm has been successfully implemented on radarsat-2 image of San Francisco bay area. Digital elevation models (DEMs) of the area under consideration are used as the 3d models of the target area. DEMs of different resolutions have been used to simulate SAR images in order to study how the target models affect the accuracy of simulation algorithm. The simulated images have been compared with radarsat-2 images to observe the efficiency of the simulation algorithm in accurately representing the locations and extents of different objects in the target area. The simulated algorithm implemented in this paper has given satisfactory results as the simulated images accurately show the different features present in the DEM of the target area.

scholarly journals Editorial for the Special Issue “Urban Deformation Monitoring using Persistent Scatterer Interferometry and SAR Tomography”

2019 ◽  
Vol 11 (11) ◽  
pp. 1306
Author(s):  
Alessandra Budillon ◽  
Michele Crosetto ◽  
Oriol Monserrat
Keyword(s):  
Synthetic Aperture Radar ◽  
Urban Areas ◽  
Deformation Monitoring ◽  
Synthetic Aperture ◽  
Special Issue ◽  
Persistent Scatterer Interferometry ◽  
Persistent Scatterer ◽  
Wide Range ◽  
Interferometric Sar ◽  
Aperture Radar

This Special Issue hosts papers related to deformation monitoring in urban areas based on two main techniques: Persistent Scatterer Interferometry (PSI) and Synthetic Aperture Radar (SAR) Tomography (TomoSAR). Several contributions highlight the capabilities of Interferometric SAR (InSAR) and PSI techniques for urban deformation monitoring. In this Special Issue, a wide range of InSAR and PSI applications are addressed. Some contributions show the advantages of TomoSAR in un-mixing multiple scatterers for urban mapping and monitoring. This issue includes a contribution that compares PSI and TomoSAR and another one that uses polarimetric data for TomoSAR.

scholarly journals Improving Urban Flood Mapping by Merging Synthetic Aperture Radar-Derived Flood Footprints with Flood Hazard Maps

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1577
Author(s):  
David C. Mason ◽  
John Bevington ◽  
Sarah L. Dance ◽  
Beatriz Revilla-Romero ◽  
Richard Smith ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Real Time ◽  
Rural Areas ◽  
Urban Areas ◽  
Flood Hazard ◽  
Synthetic Aperture ◽  
Hazard Maps ◽  
Urban Flood ◽  
Flood Hazard Maps ◽  
Aperture Radar

Remotely sensed flood extents obtained in near real-time can be used for emergency flood incident management and as observations for assimilation into flood forecasting models. High-resolution synthetic aperture radar (SAR) sensors have the potential to detect flood extents in urban areas through clouds during both day- and night-time. This paper considers a method for detecting flooding in urban areas by merging near real-time SAR flood extents with model-derived flood hazard maps. This allows a two-way symbiosis, whereby currently available SAR urban flood extent improves future model flood predictions, while flood hazard maps obtained after the SAR overpasses improve the SAR estimate of urban flood extents. The method estimates urban flooding using SAR backscatter only in rural areas adjacent to urban ones. It was compared to an existing method using SAR returns in both rural and urban areas. The method using SAR solely in rural areas gave an average flood detection accuracy of 94% and a false positive rate of 9% in the urban areas and was more accurate than the existing method.

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