{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T15:21:58Z","timestamp":1773156118079,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2022,12,6]],"date-time":"2022-12-06T00:00:00Z","timestamp":1670284800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["62107033"],"award-info":[{"award-number":["62107033"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2022-JCJQ-JJ-0202"],"award-info":[{"award-number":["2022-JCJQ-JJ-0202"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["Y21-RCFYJQ1-05"],"award-info":[{"award-number":["Y21-RCFYJQ1-05"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"National Defense Science and Technology Foundation Strengthening Plan Fund","award":["62107033"],"award-info":[{"award-number":["62107033"]}]},{"name":"National Defense Science and Technology Foundation Strengthening Plan Fund","award":["2022-JCJQ-JJ-0202"],"award-info":[{"award-number":["2022-JCJQ-JJ-0202"]}]},{"name":"National Defense Science and Technology Foundation Strengthening Plan Fund","award":["Y21-RCFYJQ1-05"],"award-info":[{"award-number":["Y21-RCFYJQ1-05"]}]},{"name":"Outstanding Youth Foundation of the Xi\u2019an branch, the Fifth Academy, Aerospace Science, and Technology Group","award":["62107033"],"award-info":[{"award-number":["62107033"]}]},{"name":"Outstanding Youth Foundation of the Xi\u2019an branch, the Fifth Academy, Aerospace Science, and Technology Group","award":["2022-JCJQ-JJ-0202"],"award-info":[{"award-number":["2022-JCJQ-JJ-0202"]}]},{"name":"Outstanding Youth Foundation of the Xi\u2019an branch, the Fifth Academy, Aerospace Science, and Technology Group","award":["Y21-RCFYJQ1-05"],"award-info":[{"award-number":["Y21-RCFYJQ1-05"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>For distributed satellite constellations, detection performance can be equivalently regarded as a single large satellite by the cooperative operation of multiple small satellites, which is a promising research topic of the Next-Generation Radar (NGR) system. However, dense grating lobes inevitably occur in the synthetic transmit pattern due to its distributed configuration, as a result of which the detection performance of dynamic coherent radar is seriously weakened. In this paper, a novel transmit beampattern optimization method for dynamic coherent radar based on a distributed satellite constellation is presented. Firstly, the effective coherent detection range interval is determined by several influence factors, i.e., coherent detection, far-field, and system link constraints. Then, we discuss the quantitative evaluation method for coherent integration in terms of synchronization error, beam pointing error, and high-speed motion characteristics and we allocate the corresponding terms in a reasonable way from the perspective of engineering. Finally, the space\u2013time\u2013frequency degrees of freedom (DOFs), which can be collected from satellite spacing, carrier frequencies, and platform motion characteristics, are utilized to realize a robust transmit beampattern with low sidelobe by invoking a genetic algorithm (GA). Simulation results validate the effectiveness of our theoretic analysis, and unambiguous coherent transmit beamforming with a satellite constellation of limited scale is accomplished.<\/jats:p>","DOI":"10.3390\/rs14236181","type":"journal-article","created":{"date-parts":[[2022,12,7]],"date-time":"2022-12-07T04:00:37Z","timestamp":1670385637000},"page":"6181","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Transmit Beampattern Design for Distributed Satellite Constellation Based on Space\u2013Time\u2013Frequency DoFs"],"prefix":"10.3390","volume":"14","author":[{"given":"Xiaomin","family":"Tan","sequence":"first","affiliation":[{"name":"School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China"},{"name":"National Key Laboratory of Science and Technology on Space Microwave, Xi\u2019an 710000, China"},{"name":"Xi\u2019an Institute of Space Radio Technology, Xi\u2019an 710000, China"}]},{"given":"Chongdi","family":"Duan","sequence":"additional","affiliation":[{"name":"Xi\u2019an Institute of Space Radio Technology, Xi\u2019an 710000, China"}]},{"given":"Yu","family":"Li","sequence":"additional","affiliation":[{"name":"Xi\u2019an Institute of Space Radio Technology, Xi\u2019an 710000, China"}]},{"given":"Jinming","family":"Chen","sequence":"additional","affiliation":[{"name":"Xi\u2019an Institute of Space Radio Technology, Xi\u2019an 710000, China"}]},{"given":"Jianping","family":"An","sequence":"additional","affiliation":[{"name":"School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,6]]},"reference":[{"key":"ref_1","unstructured":"Ticker, R., and Azzolini, J. 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