{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:25:07Z","timestamp":1760235907737,"version":"build-2065373602"},"reference-count":18,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2021,10,11]],"date-time":"2021-10-11T00:00:00Z","timestamp":1633910400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The zero-Doppler centroid control in geosynchronous synthetic aperture radar (GEO SAR) is beneficial to reduce the imaging complexity (reduces range-azimuth coupling in received data), which can be realized by adjusting the radar line of sight (RLS). In order to maintain the zero-Doppler centroid throughout the whole orbit of the GEO SAR satellite, the RLS needs to be adjusted in real-time. Due to the ultra-long synthetic aperture time of GEO SAR, the RLS variation during the synthetic aperture time cannot be neglected. However, in the previous related papers, the real-time variation of RLS during the synthetic aperture time was not taken into account in the calculation of Doppler parameters, which are closely related to the RLS, resulting in inaccurate calculation of Doppler parameters. Considering this issue, an accurate Doppler model (the model of relative motion between satellite and ground target) of GEO SAR is proposed in this paper for the accurate calculation of Doppler parameters (Doppler centroid and Doppler bandwidth and other parameters). Finally, simulation experiments are designed to confirm the effectiveness and necessity of the proposed model. The results indicate that the RLS variation during the synthetic aperture time has a considerable effect on Doppler parameters performance of the GEO SAR, and refers to a more stable azimuth resolution performance (the resolution is kept near a relatively stable value at most positions of the elliptical orbit) compared with the case that does not consider the real-time zero-Doppler centroid control.<\/jats:p>","DOI":"10.3390\/rs13204061","type":"journal-article","created":{"date-parts":[[2021,10,11]],"date-time":"2021-10-11T21:45:32Z","timestamp":1633988732000},"page":"4061","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["An Accurate Doppler Parameters Calculation Method of Geosynchronous SAR Considering Real-Time Zero-Doppler Centroid Control"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9070-7186","authenticated-orcid":false,"given":"Faguang","family":"Chang","sequence":"first","affiliation":[{"name":"College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China"}]},{"given":"Chunrui","family":"Yu","sequence":"additional","affiliation":[{"name":"Beijing Institute of Tracking and Telecommunication Technology, Beijing 100094, China"}]},{"given":"Dexin","family":"Li","sequence":"additional","affiliation":[{"name":"College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China"}]},{"given":"Yifei","family":"Ji","sequence":"additional","affiliation":[{"name":"College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China"}]},{"given":"Zhen","family":"Dong","sequence":"additional","affiliation":[{"name":"College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,11]]},"reference":[{"key":"ref_1","unstructured":"Tomiyasu, K. (1978, January 15\u201319). Synthetic aperture radar in geosynchronous orbit. Proceedings of the Digest International IEEE Antennas Propagation Symposium, College Park, MD, USA."},{"key":"ref_2","first-page":"1","article-title":"Options for continuous radar Earth observations","volume":"60","author":"Guarnieri","year":"2017","journal-title":"China Sci. Inf. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"060305","DOI":"10.1007\/s11432-017-9081-3","article-title":"Laplace plane and low inclination geosynchronous radar mission design","volume":"60","author":"Hobbs","year":"2017","journal-title":"China Sci. Inf. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1016\/j.fmre.2021.04.008","article-title":"Research progress on geosynchronous synthetic aperture radar","volume":"1","author":"Hu","year":"2021","journal-title":"Fundam. Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2286","DOI":"10.1109\/LGRS.2015.2470516","article-title":"Generalized omega-K algorithm for geosynchronous SAR image formation","volume":"12","author":"Hu","year":"2015","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1109\/LGRS.2005.844591","article-title":"Total Zero Doppler Steering-A New Method for Minimizing the Doppler Centroid","volume":"2","author":"Fiedler","year":"2005","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_7","unstructured":"Boerner, E., Fiedler, H., Krieger, G., and Mittermayer, J. (2004, January 20\u201324). A new Method for Total Zero Doppler Steering. Proceedings of the IGASS \u201904, Anchorage, AK, USA."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1080\/01431168608948916","article-title":"Doppler properties of radars in circular orbits","volume":"7","author":"Raney","year":"1986","journal-title":"Int. J. Remote Sens."},{"key":"ref_9","unstructured":"Chang, C., and Curlander, J. (1992, January 26\u201329). Attitude steering for space shuttle based synthetic aperture radrs. Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Houston, TX, USA."},{"key":"ref_10","unstructured":"Dong, X., Ding, Z., and Zhao, Z. (2010, January 7\u201310). A method of zero Doppler centroid control in GEO SAR. Proceedings of the EUSAR 2010, Aachen, Germany."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.actaastro.2006.02.005","article-title":"Geosynchronous synthetic aperture radar: Concept design, properties and possible applications","volume":"59","author":"Bruno","year":"2006","journal-title":"Acta Astronaut."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Moussessian, A., Chen, C., Edelstein, W., Madsen, S., and Rosen, P. (2005). System Concepts and Technologies for High Orbit SAR, Jet Propulsion Laboratory, California Institute of Technology.","DOI":"10.1109\/MWSYM.2005.1517017"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2014","DOI":"10.1155\/2014\/549269","article-title":"Study on Zero-Doppler Centroid Control for GEO SAR Ground Observation","volume":"2014","author":"Jiang","year":"2014","journal-title":"Int. J. Antennas Propag."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1109\/LGRS.2010.2089969","article-title":"A new method of zero-Doppler centroid control in GEO SAR","volume":"8","author":"Long","year":"2011","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_15","unstructured":"Bao, M., Liao, Y., Tian, Z.J., Xing, M.D., and Li, Y.C. (2011, January 24\u201327). Imaging algorithm for GEO SAR based on series reversion. Proceedings of the IEEE CIE International Conference on Radar, Xi\u2019an, China."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"824","DOI":"10.1109\/7.705890","article-title":"A new fourth-order processing algorithm for spaceborne SAR","volume":"34","year":"1998","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_17","unstructured":"Hu, C., and Tao, Z. (2010, January 7\u201310). The accurate resolution analysis in Geosynchronous SAR. Proceedings of the 8th European Conference on Synthetic Aperture Radar, Aachen, Germany."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Chang, F.G., and Li, D.X. (2021). Elevation Spatial variation Analysis and Compensation in GEO SAR Imaging. Remote Sens., 13.","DOI":"10.3390\/rs13101888"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/20\/4061\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:11:43Z","timestamp":1760166703000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/20\/4061"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,10,11]]},"references-count":18,"journal-issue":{"issue":"20","published-online":{"date-parts":[[2021,10]]}},"alternative-id":["rs13204061"],"URL":"https:\/\/doi.org\/10.3390\/rs13204061","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2021,10,11]]}}}