{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,17]],"date-time":"2026-05-17T00:13:34Z","timestamp":1778976814506,"version":"3.51.4"},"reference-count":38,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2020,5,26]],"date-time":"2020-05-26T00:00:00Z","timestamp":1590451200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Equipment Pre-research Foundation of China","award":["JZX7Y20190253041401, JZX7Y20190253040501, and JZX7Y20190253040901"],"award-info":[{"award-number":["JZX7Y20190253041401, JZX7Y20190253040501, and JZX7Y20190253040901"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>In a multichannel geosynchronous spaceborne\u2013airborne bistatic synthetic aperture radar (GEO-SA-BiSAR) system, the airborne receiver can obtain high-resolution microwave images with good signal-to-noise ratios (SNRs) by passively receiving echoes from the desired area. Since the Doppler modulation and range history of a moving target are obviously different from a stationary target, a signal geometry model for moving targets in multichannel GEO-SA-BiSAR is established in this paper. According to simulation results, the along track velocity introduces target defocusing in azimuth, and the slant range velocity mainly causes multiple false targets. To resolve these problems, a modified multichannel reconstruction method in azimuth channel GEO-SA-BiSAR is proposed according to the azimuth multichannel impulse response of the imaged moving target. Before azimuth multichannel raw data combination, both spatial-variant range cell migration correction (RCMC) and azimuth nonlinear chirp scaling (ANLCS) should be performed to reduce the influence of the range offset and lower the Doppler bandwidth of the whole raw data, respectively. Afterward, a novel azimuth multichannel reconstruction algorithm is carried out via the modified reconstruction matrix based on the estimated target velocity. The target slant range velocity estimation is implemented by introducing the signal intensity ratio (SIR). Compared with the conventional method for the stationary target to handle the raw data of the moving target, the false targets could be obviously suppressed by using the proposed approach. Imaging results on both simulated point and distributed scene targets validate the proposed multichannel reconstruction approach.<\/jats:p>","DOI":"10.3390\/rs12111703","type":"journal-article","created":{"date-parts":[[2020,5,28]],"date-time":"2020-05-28T12:36:58Z","timestamp":1590669418000},"page":"1703","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Azimuth Multichannel Reconstruction for Moving Targets in Geosynchronous Spaceborne\u2013Airborne Bistatic SAR"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8045-8817","authenticated-orcid":false,"given":"Wei","family":"Xu","sequence":"first","affiliation":[{"name":"College of Information Engineering, Inner Mongolia University of Technology, Hohhot 010050, Inner Mongolia, China"},{"name":"Inner Mongolia Key Laboratory of Radar Technology and Application, Hohhot 010050, Inner Mongolia, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhengbin","family":"Wei","sequence":"additional","affiliation":[{"name":"College of Information Engineering, Inner Mongolia University of Technology, Hohhot 010050, Inner Mongolia, China"},{"name":"Inner Mongolia Key Laboratory of Radar Technology and Application, Hohhot 010050, Inner Mongolia, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7720-1183","authenticated-orcid":false,"given":"Pingping","family":"Huang","sequence":"additional","affiliation":[{"name":"College of Information Engineering, Inner Mongolia University of Technology, Hohhot 010050, Inner Mongolia, China"},{"name":"Inner Mongolia Key Laboratory of Radar Technology and Application, Hohhot 010050, Inner Mongolia, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9071-9470","authenticated-orcid":false,"given":"Weixian","family":"Tan","sequence":"additional","affiliation":[{"name":"College of Information Engineering, Inner Mongolia University of Technology, Hohhot 010050, Inner Mongolia, China"},{"name":"Inner Mongolia Key Laboratory of Radar Technology and Application, Hohhot 010050, Inner Mongolia, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bo","family":"Liu","sequence":"additional","affiliation":[{"name":"Chinese Academy of Space Technology, Qian Xuesen Laboratory of Space Technology, Beijing 100094, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhiqi","family":"Gao","sequence":"additional","affiliation":[{"name":"College of Information Engineering, Inner Mongolia University of Technology, Hohhot 010050, Inner Mongolia, China"},{"name":"Inner Mongolia Key Laboratory of Radar Technology and Application, Hohhot 010050, Inner Mongolia, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3155-6437","authenticated-orcid":false,"given":"Yifan","family":"Dong","sequence":"additional","affiliation":[{"name":"College of Information Engineering, Inner Mongolia University of Technology, Hohhot 010050, Inner Mongolia, China"},{"name":"Inner Mongolia Key Laboratory of Radar Technology and Application, Hohhot 010050, Inner Mongolia, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,26]]},"reference":[{"key":"ref_1","unstructured":"Cumming, I.G., and Wong, F.H. (2005). Digital Processing of Synthetic Aperture Radar Data: Algorithms and Implementation, Artech House."},{"key":"ref_2","unstructured":"Tomiyasu, K. (1978, January 15\u201319). Synthetic aperture radar in geosynchronous orbit. Proceedings of the 1978 Antennas and Propagation Society International Symposium, Washington, DC, USA."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1109\/TGRS.1981.350361","article-title":"Conceptual Performance of a Satellite Borne, Wide Swath Synthetic Aperture Radar","volume":"2","author":"Tomiyasu","year":"1981","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1109\/PROC.1978.10961","article-title":"Tutorial review of synthetic-aperture radar (SAR) with applications to imaging of the ocean surface","volume":"66","author":"Tomiyasu","year":"1978","journal-title":"Proc. IEEE"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1109\/TGRS.1983.350561","article-title":"Synthetic Aperture Radar Imaging from an Inclined Geosynchronous Orbit","volume":"21","author":"Tomiyasu","year":"1983","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1109\/MGRS.2013.2248301","article-title":"A tutorial on synthetic aperture radar","volume":"1","author":"Moreira","year":"2013","journal-title":"IEEE Geosci. Remote Sens. Mag."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1109\/MGRS.2015.2437353","article-title":"Tandem-L: A Highly Innovative Bistatic SAR Mission for Global Observation of Dynamic Processes on the Earth\u2019s Surface","volume":"3","author":"Moreira","year":"2015","journal-title":"IEEE Geosci. Remote Sens. Mag."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3548","DOI":"10.1109\/TGRS.2011.2160402","article-title":"The Accurate Focusing and Resolution Analysis Method in Geosynchronous SAR","volume":"49","author":"Hu","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"7750","DOI":"10.1109\/TGRS.2014.2318171","article-title":"System Design for Geosynchronous Synthetic Aperture Radar Missions","volume":"52","author":"Hobbs","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1109\/TGRS.2015.2457034","article-title":"Inclined Geosynchronous Spaceborne\u2013Airborne Bistatic SAR: Performance Analysis and Mission Design","volume":"54","author":"Sun","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1109\/LGRS.2012.2197850","article-title":"Resolution Calculation and Analysis in Bistatic SAR With Geostationary Illuminator","volume":"10","author":"Wang","year":"2013","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1590","DOI":"10.1109\/LGRS.2019.2902036","article-title":"Geosynchronous Spaceborne-Airborne Multichannel Bistatic SAR Imaging Using Weighted Fast Factorized Backprojection Method","volume":"16","author":"An","year":"2019","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2380","DOI":"10.1109\/LGRS.2017.2765675","article-title":"High-Resolution Wide-Swath Imaging of Spaceborne Multichannel Bistatic SAR with Inclined Geosynchronous Illuminator","volume":"14","author":"Wang","year":"2017","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1861","DOI":"10.1109\/TGRS.2018.2869835","article-title":"Azimuth Signal Multichannel Reconstruction and Channel ConFigureuration Design for Geosynchronous Spaceborne\u2013Airborne Bistatic SAR","volume":"57","author":"Wu","year":"2019","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3459","DOI":"10.1109\/TGRS.2008.923322","article-title":"Phase Synchronization and Doppler Centroid Estimation in Fixed Receiver Bistatic SAR Systems","volume":"46","author":"Mallorqui","year":"2008","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5019","DOI":"10.1109\/TGRS.2013.2276048","article-title":"Extended NLCS Algorithm of BiSAR Systems With a Squinted Transmitter and a Fixed Receiver: Theory and Experimental Confirmation","volume":"51","author":"Zeng","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3980","DOI":"10.1109\/JSTARS.2019.2939194","article-title":"COBIS: Opportunistic C-Band Bistatic SAR Differential Interferometry","volume":"12","author":"Anghel","year":"2019","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5015","DOI":"10.1109\/JSTARS.2015.2450019","article-title":"Simultaneous High-Resolution Wide-Swath SAR Imaging and Ground Moving Target Indication: Processing Approaches and System Concepts","volume":"8","author":"Baumgartner","year":"2015","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"782","DOI":"10.1109\/LGRS.2009.2025245","article-title":"Azimuth Phase Center Adaptation on Transmit for High-Resolution Wide-Swath SAR Imaging","volume":"6","author":"Gebert","year":"2009","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"728","DOI":"10.1109\/LGRS.2013.2278183","article-title":"Investigation on Full-Aperture Multichannel Azimuth Data Processing in TOPS","volume":"11","author":"Huang","year":"2014","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"4417","DOI":"10.1109\/TGRS.2013.2265306","article-title":"Processing of Multichannel Sliding Spotlight and TOPS Synthetic Aperture Radar Data","volume":"51","author":"Xu","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"143780","DOI":"10.1109\/ACCESS.2019.2944871","article-title":"Azimuth Phase Coding by Up and Down Chirp Modulation for Range Ambiguity Suppression","volume":"7","author":"Xu","year":"2019","journal-title":"IEEE Access"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Xu, W., Hu, J., Huang, P., Tan, W., and Dong, Y. (2019). Azimuth Phase Center Adaptive Adjustment upon Reception for High-Resolution Wide-Swath Imaging. Sensors, 19.","DOI":"10.3390\/s19194277"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3713","DOI":"10.1109\/TGRS.2018.2886817","article-title":"A Two-Step Nonlinear Chirp Scaling Method for Multichannel GEO Spaceborne\u2013Airborne Bistatic SAR Spectrum Reconstructing and Focusing","volume":"57","author":"An","year":"2019","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Wu, J., Sun, Z., Li, Z., Huang, Y., Yang, J., and Liu, Z. (2016). Focusing translational variant bistatic forward-looking SAR using keystone transform and extended nonlinear chirp scaling. Remote Sens., 8.","DOI":"10.3390\/rs8100840"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1270","DOI":"10.3390\/s17061270","article-title":"Investigation of Azimuth Multichannel Reconstruction for Moving Targets in High Resolution Wide Swath SAR","volume":"17","author":"Tan","year":"2017","journal-title":"Sensors"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1000","DOI":"10.1109\/TAES.2014.130539","article-title":"Bistatic Forward-Looking SAR Ground Moving Target Detection and Imaging","volume":"51","author":"Li","year":"2015","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_28","unstructured":"Zhao, B., Qi, X., Deng, Y., Wang, R., and Song, H. (2012, January 24\u201326). Accurate fourth-order doppler parameter estimation approach for geosynchronous SAR. Proceedings of the EUSAR 2012; 9th European Conference on Synthetic Aperture Radar, Nuremberg, Germany."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"6379","DOI":"10.1109\/TGRS.2013.2296357","article-title":"Nearly Zero Inclination Geosynchronous SAR Mission Analysis With Long Integration Time for Earth Observation","volume":"52","author":"Broquetas","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1119","DOI":"10.1109\/JSTARS.2015.2497000","article-title":"A Modified Frequency Domain Algorithm Based on Optimal Azimuth Quadratic Factor Compensation for Geosynchronous SAR Imaging","volume":"9","author":"Ding","year":"2016","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1109\/TCS.1977.1084284","article-title":"Generalized sampling expansion","volume":"24","author":"Papoulis","year":"1977","journal-title":"IEEE Trans. Circuits Syst."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4611","DOI":"10.1109\/TGRS.2013.2264732","article-title":"Multichannel Azimuth Processing in ScanSAR and TOPS Mode Operation","volume":"51","author":"Gebert","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1109\/LGRS.2013.2250904","article-title":"Focusing Bistatic Forward-Looking SAR With Stationary Transmitter Based on Keystone Transform and Nonlinear Chirp Scaling","volume":"11","author":"Wu","year":"2014","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"4005","DOI":"10.1109\/TGRS.2013.2278701","article-title":"Suppression of Clutter in Multichannel SAR GMTI","volume":"52","author":"Sjogren","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2831","DOI":"10.3724\/SP.J.1146.2007.00923","article-title":"The Clutter Suppression Method of Airborne Multi-channel SAR-GMTI System","volume":"30","author":"Yang","year":"2011","journal-title":"J. Electron. Inf. Technol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1109\/TGRS.2014.2327031","article-title":"Robust Clutter Suppression and Moving Target Imaging Approach for Multichannel in Azimuth High-Resolution and Wide-Swath Synthetic Aperture Radar","volume":"53","author":"Zhang","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1416","DOI":"10.1109\/TAES.2002.1145767","article-title":"Application of the fractional Fourier transform to moving target detection in airborne SAR","volume":"38","author":"Sun","year":"2002","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1109\/LGRS.2006.882147","article-title":"A Keystone Transform Without Interpolation for SAR Ground Moving-Target Imaging","volume":"4","author":"Zhu","year":"2007","journal-title":"IEEE Geosci. Remote Sens. Lett."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/11\/1703\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:32:51Z","timestamp":1760175171000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/11\/1703"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,5,26]]},"references-count":38,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2020,6]]}},"alternative-id":["rs12111703"],"URL":"https:\/\/doi.org\/10.3390\/rs12111703","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,5,26]]}}}