Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048396
Lulu Tan, Yan Wang, Lei Sheng
Due to its all-weather, day and night imaging capability, Synthetic Aperture Radar (SAR) is playing a very important role in earth observation. Satellites loaded with SAR payload are widely used in military and civilian applications due to its high resolution, wide swath imaging and global coverage capabilities. However, the applilcation of SAR satellites is severely restricted by its costs and weights. In this paper, a low-cost payload platform integrated SAR system with high resolution is proposed. The instruments of the system is described and the performance of the system is illustrated.
{"title":"A high performance low-cost SAR system loaded on small satellite platform","authors":"Lulu Tan, Yan Wang, Lei Sheng","doi":"10.1109/APSAR46974.2019.9048396","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048396","url":null,"abstract":"Due to its all-weather, day and night imaging capability, Synthetic Aperture Radar (SAR) is playing a very important role in earth observation. Satellites loaded with SAR payload are widely used in military and civilian applications due to its high resolution, wide swath imaging and global coverage capabilities. However, the applilcation of SAR satellites is severely restricted by its costs and weights. In this paper, a low-cost payload platform integrated SAR system with high resolution is proposed. The instruments of the system is described and the performance of the system is illustrated.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133217837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048554
Zhan Zhenxian, Xu Tanghong, Huang Shuaishuai
A Ku-band broadband waveguide wide side longitudinal slot antenna array for unmanned aerial vehicle (UAV) SAR application is designed. A single-ridge is employed to reduce the sectional size of the waveguide, and to achieve wide scanning ability. The bandwidth of the antenna is expanded by the single-ridge and subarea feeding of the slots. The active admittance of the waveguide slot is extracted based on the simulation using the HFSS software, in order to determine the size parameters of the waveguide slots. The simulation mode is built and the size parameters of the waveguide slots are modified and optimized by the aperture distribution re-deducing method. This design method has high efficiency and high veracity. An antenna array of 72 waveguide slot antenna lines is designed and manufactured. The measured results show that the relative bandwidth of VSWR smaller than 2 is 15%. The measured patterns show that the side lobe is smaller than −21.5dB, the cross polarization is better than −40dB, and the scanning angle is ±60° in azimuth direction. This waveguide slot antenna array has many advantages such as wide band, wide scanning, low side lobe and compact structure, and is suitable for UAV SAR application.
{"title":"A Ku-band Broadband Single-Ridge Waveguide Slot Antenna Array for UAV SAR Application","authors":"Zhan Zhenxian, Xu Tanghong, Huang Shuaishuai","doi":"10.1109/APSAR46974.2019.9048554","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048554","url":null,"abstract":"A Ku-band broadband waveguide wide side longitudinal slot antenna array for unmanned aerial vehicle (UAV) SAR application is designed. A single-ridge is employed to reduce the sectional size of the waveguide, and to achieve wide scanning ability. The bandwidth of the antenna is expanded by the single-ridge and subarea feeding of the slots. The active admittance of the waveguide slot is extracted based on the simulation using the HFSS software, in order to determine the size parameters of the waveguide slots. The simulation mode is built and the size parameters of the waveguide slots are modified and optimized by the aperture distribution re-deducing method. This design method has high efficiency and high veracity. An antenna array of 72 waveguide slot antenna lines is designed and manufactured. The measured results show that the relative bandwidth of VSWR smaller than 2 is 15%. The measured patterns show that the side lobe is smaller than −21.5dB, the cross polarization is better than −40dB, and the scanning angle is ±60° in azimuth direction. This waveguide slot antenna array has many advantages such as wide band, wide scanning, low side lobe and compact structure, and is suitable for UAV SAR application.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133029487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048389
Jianghong Han, Gang Li, Xiao-Ping Zhang
In this paper, we present a new scheme of adaptive quantization thresholds for one-bit radar imaging based on adversarial samples. Radar imaging with one-bit compressive sensing (CS) is attractive due to the small storage burden and low requirements to the analog-to-digital converter. However, conventional one-bit quantization scheme with fixed thresholds does not use the magnitude information, possibly leading to difficulty in energy estimation and higher amplitude recovery error. Recently, adaptive thresholds methods have been developed to deal with the limitation of fixed thresholds scheme. Based on the adversarial training theory, the proposed new method embeds adversarial samples into the binary iterative hard thresholding (BIHT) algorithm and exploits an adaptive thresholds scheme based on the adversarial samples to improve the model robustness and imaging quality with one-bit coded data. Simulation results demonstrate that the proposed method outperforms the BIHT with fixed thresholds in one-bit radar imaging.
{"title":"Design of Adaptive Thresholds For One-Bit Radar Imaging Based on Adversarial Samples","authors":"Jianghong Han, Gang Li, Xiao-Ping Zhang","doi":"10.1109/APSAR46974.2019.9048389","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048389","url":null,"abstract":"In this paper, we present a new scheme of adaptive quantization thresholds for one-bit radar imaging based on adversarial samples. Radar imaging with one-bit compressive sensing (CS) is attractive due to the small storage burden and low requirements to the analog-to-digital converter. However, conventional one-bit quantization scheme with fixed thresholds does not use the magnitude information, possibly leading to difficulty in energy estimation and higher amplitude recovery error. Recently, adaptive thresholds methods have been developed to deal with the limitation of fixed thresholds scheme. Based on the adversarial training theory, the proposed new method embeds adversarial samples into the binary iterative hard thresholding (BIHT) algorithm and exploits an adaptive thresholds scheme based on the adversarial samples to improve the model robustness and imaging quality with one-bit coded data. Simulation results demonstrate that the proposed method outperforms the BIHT with fixed thresholds in one-bit radar imaging.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115508936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048421
Fangfang Li, Yueting Zhang, Xiaolan Qiu
Spaceborne Interferometric Synthetic Aperture Radar (InSAR) has the capability of high precise topographic mapping for large area. However, on the one hand, digital elevation models (DEM) inversion needs at least one ground control points (GCP) to obtain absolute interferometric phase as the unwrapped phase is just a relative value. On the other hand, the baseline value used for DEM inversion also needs to be calibrated using GCPs due to the measure error. In practice, it is difficult to manually deploy GCPs especially in the area of steep topography. At present, with the improvement of orbital measure accuracy and system time accuracy for spaceborne SAR satellite, high precise absolute 3D location information of some stable point scatterers can be obtained by stereo SAR using data from different viewing angles. Therefore, this paper combines stereo SAR with InSAR. These point scatters are used as GCPs to calibrate baseline and estimate absolute phase. As a result, high accurate DEM generation without GCPs can be achieved. The experiment using TerraSAR-X data verifies the effectiveness of this method.
{"title":"An Approach for Spaceborne InSAR DEM Inversion Integrated with Stereo-SAR Method","authors":"Fangfang Li, Yueting Zhang, Xiaolan Qiu","doi":"10.1109/APSAR46974.2019.9048421","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048421","url":null,"abstract":"Spaceborne Interferometric Synthetic Aperture Radar (InSAR) has the capability of high precise topographic mapping for large area. However, on the one hand, digital elevation models (DEM) inversion needs at least one ground control points (GCP) to obtain absolute interferometric phase as the unwrapped phase is just a relative value. On the other hand, the baseline value used for DEM inversion also needs to be calibrated using GCPs due to the measure error. In practice, it is difficult to manually deploy GCPs especially in the area of steep topography. At present, with the improvement of orbital measure accuracy and system time accuracy for spaceborne SAR satellite, high precise absolute 3D location information of some stable point scatterers can be obtained by stereo SAR using data from different viewing angles. Therefore, this paper combines stereo SAR with InSAR. These point scatters are used as GCPs to calibrate baseline and estimate absolute phase. As a result, high accurate DEM generation without GCPs can be achieved. The experiment using TerraSAR-X data verifies the effectiveness of this method.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114267837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048317
You Wu, Q. Yin, Fan Zhang
Polarimetric Synthetic Aperture Radar (PolSAR) can obtain ground polarization information by transmitting and receiving polarized waves. The polarization information of the ground soil can be inverted to the moisture and roughness information by the empirical models. With the massive increase of PolSAR data, the demand for efficient processing is gradually growing. In this paper, a GPU based surface parameter parallel inversion method is proposed to solve this issue in quantitative remote sensing. This paper improves computational efficiency by using instruction set optimization, algorithm redundancy optimization, and fast numerical operations. The experimental results show that the method can realize approximately 100 times faster than the original serial version on CPU. If only the calculation part is considered, the method should achieve more than 1000 times acceleration.
{"title":"GPU-Based Soil Parameter Parallel Inversion for PolSAR Imagery","authors":"You Wu, Q. Yin, Fan Zhang","doi":"10.1109/APSAR46974.2019.9048317","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048317","url":null,"abstract":"Polarimetric Synthetic Aperture Radar (PolSAR) can obtain ground polarization information by transmitting and receiving polarized waves. The polarization information of the ground soil can be inverted to the moisture and roughness information by the empirical models. With the massive increase of PolSAR data, the demand for efficient processing is gradually growing. In this paper, a GPU based surface parameter parallel inversion method is proposed to solve this issue in quantitative remote sensing. This paper improves computational efficiency by using instruction set optimization, algorithm redundancy optimization, and fast numerical operations. The experimental results show that the method can realize approximately 100 times faster than the original serial version on CPU. If only the calculation part is considered, the method should achieve more than 1000 times acceleration.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114787024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048315
Yu Li, Yunhua Zhang, Xiao Dong
A new interferometric inverse synthetic aperture radar (InISAR) imaging method based on a L shape three-antenna interferometric radar geometry and dominant-scatterer phase focusing is presented in this paper. Under this InISAR model, the distance of the target in the baseline direction introduces additional interferometric phase offset, which can cause phase ambiguity, so the interferometric phase must be corrected before interferometric processing. Firstly, a strong scattering point is searched for as a reference point in the image domain, and then the phase of the scattering point is used as the reference phase for phase focusing on each ISAR image respectively to unwrap the interferometric phase, so that the 3D coordinates of the target can be correctly retrieved. Simulation results confirm the effectiveness of the method.
{"title":"An InISAR Imaging Method Based on Dominant-Scatterer Phase Focusing","authors":"Yu Li, Yunhua Zhang, Xiao Dong","doi":"10.1109/APSAR46974.2019.9048315","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048315","url":null,"abstract":"A new interferometric inverse synthetic aperture radar (InISAR) imaging method based on a L shape three-antenna interferometric radar geometry and dominant-scatterer phase focusing is presented in this paper. Under this InISAR model, the distance of the target in the baseline direction introduces additional interferometric phase offset, which can cause phase ambiguity, so the interferometric phase must be corrected before interferometric processing. Firstly, a strong scattering point is searched for as a reference point in the image domain, and then the phase of the scattering point is used as the reference phase for phase focusing on each ISAR image respectively to unwrap the interferometric phase, so that the 3D coordinates of the target can be correctly retrieved. Simulation results confirm the effectiveness of the method.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"2015 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114445501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multi-input and multi-output SAR (MIMO-SAR) processing technique is the important development trend of the next-generation spaceborne SAR imaging system, due to the ability of achieving high resolution and large swath width (HRWS) imaging by exploiting more spatial degrees of freedom via adding multiple transmission channels. Considering that multichannel MIMO-SAR signal is nonuniformly sampled and most of the conventional reconstruction algorithms are time-consuming due to the matrix inversion or the eigenvalue decomposition, this paper proposes a fast nonuniform signal reconstruction algorithm based on filterbank framework theory, which combines the non-uniform signal reconstruction theory with a bank of filters to resolve the azimuth ambiguity by the point multiplication operation. Simulated processing results are used to validate the effectiveness of the proposed method.
{"title":"A Novel Multi-channel High-Resolution Imaging Method for MIMO-SAR System Based on Filterbank Framework Reconstruction Theory","authors":"Lingyu Wang, Penghui Huang, Xingzhao Liu, Robert Wang, Yanyang Liu, Huajian Xu","doi":"10.1109/APSAR46974.2019.9048532","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048532","url":null,"abstract":"Multi-input and multi-output SAR (MIMO-SAR) processing technique is the important development trend of the next-generation spaceborne SAR imaging system, due to the ability of achieving high resolution and large swath width (HRWS) imaging by exploiting more spatial degrees of freedom via adding multiple transmission channels. Considering that multichannel MIMO-SAR signal is nonuniformly sampled and most of the conventional reconstruction algorithms are time-consuming due to the matrix inversion or the eigenvalue decomposition, this paper proposes a fast nonuniform signal reconstruction algorithm based on filterbank framework theory, which combines the non-uniform signal reconstruction theory with a bank of filters to resolve the azimuth ambiguity by the point multiplication operation. Simulated processing results are used to validate the effectiveness of the proposed method.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114770494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048409
Moxin Zhao, Yunhua Zhang, Dong Li
This paper proposes a method to improve the contrast between ship wake and background in radar image so as to better detect the ship wake. The method is based on the white top-hat transformation with the structuring element determined by the edge orientation. By applying the white top-hat transformation on each submatrix, the contrast can be improved, which is good for detecting the location of wake in the Radon domain. The radar image containing ship wake from the TG-2 interferometric imaging radar altimeter (InIRA) is processed to test the method, and the results validate the algorithm very well.
{"title":"A novel ship wake detection method based on white top-hat transformation","authors":"Moxin Zhao, Yunhua Zhang, Dong Li","doi":"10.1109/APSAR46974.2019.9048409","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048409","url":null,"abstract":"This paper proposes a method to improve the contrast between ship wake and background in radar image so as to better detect the ship wake. The method is based on the white top-hat transformation with the structuring element determined by the edge orientation. By applying the white top-hat transformation on each submatrix, the contrast can be improved, which is good for detecting the location of wake in the Radon domain. The radar image containing ship wake from the TG-2 interferometric imaging radar altimeter (InIRA) is processed to test the method, and the results validate the algorithm very well.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115887648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048530
W. Dong, Hanwei Sun
Aiming at the error factors affecting the measurement accuracy of interferometric imaging altimeter, the error simulation method in this paper is carried out from the angle of wavenumber spectrum. The principle and process of simulation are given in this paper. And the main errors affecting the accuracy of measurement are analyzed and simulated which include: baseline inclination error, baseline length error, random noise error, sea state bias, dry tropospheric delay error, wet tropospheric delay error, ionospheric delay error, etc.
{"title":"Error Simulation Method of Interferometric Imaging Altimeter Based on Wavenumber Spectrum Analysis","authors":"W. Dong, Hanwei Sun","doi":"10.1109/APSAR46974.2019.9048530","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048530","url":null,"abstract":"Aiming at the error factors affecting the measurement accuracy of interferometric imaging altimeter, the error simulation method in this paper is carried out from the angle of wavenumber spectrum. The principle and process of simulation are given in this paper. And the main errors affecting the accuracy of measurement are analyzed and simulated which include: baseline inclination error, baseline length error, random noise error, sea state bias, dry tropospheric delay error, wet tropospheric delay error, ionospheric delay error, etc.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116069617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-01DOI: 10.1109/APSAR46974.2019.9048347
Wei Yilin, Sun Bing, Liu Liwen
As an important technology in the field of precise guidance, platform positioning technology based on SAR image matching has many advantages such as all-weather, all-time capabilities and no time cumulative error. However, the existence of various interference factors causes positioning errors. This paper concentrates on the analysis of platform positioning error based on SAR image matching, which provides significant engineering reference for platform positioning error correction. On the basis of the principle of SAR platform positioning technology, the factors influencing the platform positioning errors are sorted out. Then, the positioning error law of direct interference factors is derived, based which the platform positioning error correction method comes up innovatively. Further, the simulations for direct interference factors are carried out, which verify that the results are consistent with the theoretical assumptions and the positioning error can be corrected accurately by the correction method.
{"title":"Error Analysis of Platform Positioning Based on SAR Image Matching","authors":"Wei Yilin, Sun Bing, Liu Liwen","doi":"10.1109/APSAR46974.2019.9048347","DOIUrl":"https://doi.org/10.1109/APSAR46974.2019.9048347","url":null,"abstract":"As an important technology in the field of precise guidance, platform positioning technology based on SAR image matching has many advantages such as all-weather, all-time capabilities and no time cumulative error. However, the existence of various interference factors causes positioning errors. This paper concentrates on the analysis of platform positioning error based on SAR image matching, which provides significant engineering reference for platform positioning error correction. On the basis of the principle of SAR platform positioning technology, the factors influencing the platform positioning errors are sorted out. Then, the positioning error law of direct interference factors is derived, based which the platform positioning error correction method comes up innovatively. Further, the simulations for direct interference factors are carried out, which verify that the results are consistent with the theoretical assumptions and the positioning error can be corrected accurately by the correction method.","PeriodicalId":377019,"journal":{"name":"2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115426530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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