{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:12:24Z","timestamp":1760145144984,"version":"build-2065373602"},"reference-count":31,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2024,6,24]],"date-time":"2024-06-24T00:00:00Z","timestamp":1719187200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the National Key R&amp;D program of China","award":["2022YFB3901601"],"award-info":[{"award-number":["2022YFB3901601"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>In order to address the problems of range ambiguity and azimuth ambiguity in the wide-swath imaging of synthetic aperture radar (SAR), this paper proposes a multi-beam SAR two-dimensional ambiguity suppression method based on azimuth phase coding (APC). The scheme employs an elevation simultaneous multi-beam transmission system with azimuth under-sampling, transmitting different APC waveforms to various range-ambiguous sub-regions. After receiving the echoes, the azimuth digital beamforming (DBF) is used to separate the APC waveform echoes with multi-order Doppler ambiguity, achieving azimuth reconstruction and range ambiguity suppression simultaneously. Finally, the elevation nulling DBF is used to further suppress range ambiguity and obtain the SAR wide-swath image. The superiority of this scheme is reflected in the following aspects: the azimuth DBF simultaneously suppresses azimuth and range ambiguity, the influence of height fluctuations on the ability to suppress range ambiguity is weakened, the use of elevation nulling DBF further enhances the level of range ambiguity suppression, and different range sub-regions can adopt different range resolutions and working modes. The feasibility of this scheme is verified through theoretical analysis and simulation.<\/jats:p>","DOI":"10.3390\/rs16132298","type":"journal-article","created":{"date-parts":[[2024,6,24]],"date-time":"2024-06-24T05:16:18Z","timestamp":1719206178000},"page":"2298","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Novel Multi-Beam SAR Two-Dimensional Ambiguity Suppression Method Based on Azimuth Phase Coding"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3333-0394","authenticated-orcid":false,"given":"Yihao","family":"Xu","sequence":"first","affiliation":[{"name":"National Key Laboratory of Microwave Imaging, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]},{"given":"Fubo","family":"Zhang","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Microwave Imaging, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0029-1368","authenticated-orcid":false,"given":"Wenjie","family":"Li","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Microwave Imaging, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0732-4975","authenticated-orcid":false,"given":"Yangliang","family":"Wan","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Microwave Imaging, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"}]},{"given":"Longyong","family":"Chen","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Microwave Imaging, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-9835-9641","authenticated-orcid":false,"given":"Tao","family":"Jiang","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Microwave Imaging, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2185","DOI":"10.1109\/JSTARS.2022.3153118","article-title":"Method of high signal-to-noise ratio and wide swath SAR imaging based on continuous pulse coding","volume":"15","author":"Wei","year":"2022","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Guo, Y., Wang, Y., Liao, G., and Li, J. (2022). Mitigating Range Ambiguity Method Based on DDMA for SAR Systems. Remote Sens., 14.","DOI":"10.3390\/rs14215485"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1109\/36.823926","article-title":"The \u201cMyth\u201d of the minimum SAR antenna area constraint","volume":"38","author":"Freeman","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"938","DOI":"10.1109\/TGRS.2019.2941983","article-title":"Processing of spaceborne squinted sliding spotlight and HRWS TOPS mode data using 2-D baseband azimuth scaling","volume":"58","author":"He","year":"2019","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Chen, Y., Zhao, Y., Li, G., Wang, W., and Liu, P. (2020, January 8\u201311). High-Resolution and Wide-Swath Monostatic SAR Imaging via Random Beam Scanning. Proceedings of the 2020 IEEE 11th Sensor Array and Multichannel Signal Processing Workshop (SAM), Hangzhou, China.","DOI":"10.1109\/SAM48682.2020.9104249"},{"key":"ref_6","unstructured":"Lightstone, L., Faubert, D., and Rempel, G. (1991, January 12\u201313). Multiple phase centre DPCA for airborne radar. Proceedings of the 1991 IEEE National Radar Conference, Los Angeles, CA, USA."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1109\/LGRS.2004.832700","article-title":"Unambiguous SAR signal reconstruction from nonuniform displaced phase center sampling","volume":"1","author":"Krieger","year":"2004","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1763","DOI":"10.1109\/IGARSS.2004.1370674","article-title":"SAR signal reconstruction from non-uniform displaced phase centre sampling","volume":"Volume 3","author":"Krieger","year":"2004","journal-title":"Proceedings of the IGARSS 2004. 2004 IEEE International Geoscience and Remote Sensing Symposium"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4306","DOI":"10.1109\/TGRS.2013.2281329","article-title":"Multichannel HRWS SAR imaging based on range-variant channel calibration and multi-Doppler-direction restriction ambiguity suppression","volume":"52","author":"Zhang","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_10","unstructured":"Gebert, N. (2009). Multi-Channel Azimuth Processing for High-Resolution Wide-Swath, Universitat (TH), DLR-Forschungsbericht."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Castillo, J., Younis, M., and Krieger, G. (2017, January 11\u201313). A HRWS SAR system design with multi-beam imaging capabilities. Proceedings of the 2017 European Radar Conference (EURAD), Nuremberg, Germany.","DOI":"10.23919\/EURAD.2017.8249176"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1774","DOI":"10.1109\/TGRS.2017.2768243","article-title":"GMTI and parameter estimation for MIMO SAR system via fast interferometry RPCA method","volume":"56","author":"Huang","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2628","DOI":"10.1109\/TGRS.2013.2263934","article-title":"MIMO-SAR: Opportunities and pitfalls","volume":"52","author":"Krieger","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"11584","DOI":"10.1109\/TVT.2020.3014689","article-title":"Suppression of mainbeam deceptive jammer with FDA-MIMO radar","volume":"69","author":"Lan","year":"2020","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_15","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_16","doi-asserted-by":"crossref","unstructured":"Yu, K., Zhu, S., Lan, L., and Yang, B. (2023). High-Resolution and Wide-Swath SAR Imaging with Space\u2013Time Coding Array. Remote Sens., 15.","DOI":"10.3390\/rs15092465"},{"key":"ref_17","first-page":"1","article-title":"High-Resolution and Wide-Swath Imaging Based on Multifrequency Pulse Diversity and DPCA Technique","volume":"19","author":"Zhang","year":"2021","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1109\/LGRS.2012.2193870","article-title":"Mitigating range ambiguities in high-PRF SAR with OFDM waveform diversity","volume":"10","author":"Wang","year":"2012","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4194","DOI":"10.1109\/TGRS.2013.2280190","article-title":"Investigations on OFDM signal for range ambiguity suppression in SAR configuration","volume":"52","author":"Riche","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"336","DOI":"10.1109\/JSTSP.2016.2605064","article-title":"A range ambiguity resolution approach for high-resolution and wide-swath SAR imaging using frequency diverse array","volume":"11","author":"Wang","year":"2016","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1620","DOI":"10.1109\/JSTSP.2015.2465353","article-title":"Range ambiguous clutter suppression for airborne FDA-STAP radar","volume":"9","author":"Xu","year":"2015","journal-title":"IEEE J. Sel. Top. Signal Process."},{"key":"ref_22","first-page":"1","article-title":"A novel range-azimuth joint modulation scheme for range ambiguity suppression","volume":"60","author":"Jin","year":"2021","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_23","first-page":"1","article-title":"A novel transmitter-interpulse phase coding MIMO-radar for range ambiguity separation","volume":"60","author":"Niu","year":"2022","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4265","DOI":"10.1109\/TSP.2022.3200873","article-title":"A reconfigurable MIMO-SAR transmission scheme based on inter-pulse and intra-pulse joint phase modulation","volume":"70","author":"Jin","year":"2022","journal-title":"IEEE Trans. Signal Process."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"6525","DOI":"10.1080\/01431161.2018.1460509","article-title":"Range ambiguity suppression in a synthetic aperture radar using pulse phase coding and two-pulse cancellation","volume":"39","author":"Wang","year":"2018","journal-title":"Int. J. Remote Sens."},{"key":"ref_26","first-page":"1","article-title":"A 2-D method based on nonlinear frequency modulation waveform and phase coding for range ambiguity suppression","volume":"20","author":"Wang","year":"2023","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1556","DOI":"10.1109\/LGRS.2015.2412961","article-title":"A novel space\u2013time coding scheme used for MIMO-SAR systems","volume":"12","author":"Wang","year":"2015","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Zhou, F., Ai, J., Dong, Z., Zhang, J., and Xing, M. (2018). A novel MIMO\u2013SAR solution based on azimuth phase coding waveforms and digital beamforming. Sensors, 18.","DOI":"10.3390\/s18103374"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"8147","DOI":"10.1109\/TGRS.2020.2987630","article-title":"Range-ambiguous clutter suppression for the SAR-GMTI system based on extended azimuth phase coding","volume":"58","author":"He","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1319","DOI":"10.1109\/TGRS.2020.3001251","article-title":"Quadratically constrained ambiguity suppression algorithm for APC\/multichannel SAR systems with nonuniform spatial sampling","volume":"59","author":"Zhang","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4051","DOI":"10.1109\/TAES.2021.3082703","article-title":"Inter-pulse phase modulation waveform scheme for spaceborne MIMO SAR systems","volume":"57","author":"Wang","year":"2021","journal-title":"IEEE Trans. Aerosp. Electron. 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