{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T16:13:14Z","timestamp":1784736794852,"version":"3.55.0"},"reference-count":19,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2018,8,5]],"date-time":"2018-08-05T00:00:00Z","timestamp":1533427200000},"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":["Grant 2017YFC1405600"],"award-info":[{"award-number":["Grant 2017YFC1405600"]}]},{"name":"the Fundamental Research Funds for the Central Universities","award":["Grant JB180213"],"award-info":[{"award-number":["Grant JB180213"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Conventional synthetic aperture radar (SAR) imaging algorithms usually require a period of time to process data that is longer than the time it takes to record one synthetic aperture or that corresponding to an adequate azimuth resolution. That is to say, the real-time processing system is idle during the long data recording time and the utilization of computational resources is low. To deal with this problem, a real-time imaging algorithm based on sub-aperture chirp scaling dechirp (CS-dechirp) is proposed in this paper. With CS-dechirp, the sub-aperture data could be processed to form an image with relatively low resolution. Subsequently, a few low-resolution images are generated as longer azimuth data are recorded. At the stage of full-resolution image generation, a coherent combination method for the low-resolution complex-value images is developed. As the low-resolution complex-value images are coherently combined one by one, the resolution is gradually improved and the full-resolution image is finally obtained. The results of a simulation and real data from the GF3-SAR validate the effectiveness of the proposed algorithm.<\/jats:p>","DOI":"10.3390\/s18082562","type":"journal-article","created":{"date-parts":[[2018,8,7]],"date-time":"2018-08-07T03:44:18Z","timestamp":1533613458000},"page":"2562","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["A Real-Time Imaging Algorithm Based on Sub-Aperture CS-Dechirp for GF3-SAR Data"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6482-0863","authenticated-orcid":false,"given":"Guang-Cai","family":"Sun","sequence":"first","affiliation":[{"name":"National Laboratory of Radar Signal Processing, Xidian University, Xi\u2019an 710071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanbin","family":"Liu","sequence":"additional","affiliation":[{"name":"National Laboratory of Radar Signal Processing, Xidian University, Xi\u2019an 710071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mengdao","family":"Xing","sequence":"additional","affiliation":[{"name":"National Laboratory of Radar Signal Processing, Xidian University, Xi\u2019an 710071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shiyu","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Xidian University, Xi\u2019an 710071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liang","family":"Guo","sequence":"additional","affiliation":[{"name":"School of Physics and Optoelectronic Engineering, Xidian University, Xi\u2019an 710071, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jun","family":"Yang","sequence":"additional","affiliation":[{"name":"College of Geomatics, Xi\u2019an University of Science and Technology, Xi\u2019an 710054, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,8,5]]},"reference":[{"key":"ref_1","first-page":"4792","article-title":"Tandem-L: A Technical Perspective on Future Spaceborne SAR Sensors for Earth Observation","volume":"50","author":"Sigurd","year":"2018","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3236","DOI":"10.1109\/TGRS.2017.2666086","article-title":"Derivation of Sea Surface Tidal Current From Spaceborne SAR Constellation Data","volume":"55","author":"Ren","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"853","DOI":"10.1109\/LGRS.2018.2811786","article-title":"An Analytical Error Model for Spaceborne SAR Multichannel Azimuth Reconstruction","volume":"15","author":"Felipe","year":"2018","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_4","unstructured":"Ni, C., Tan, H., and Liu, Q. (2015, January 28\u201330). VPX based spaceborne SAR real-time echo simulation. Proceedings of the IEEE 6th International Symposium on MAPE, Shanghai, China."},{"key":"ref_5","unstructured":"Moreira, A., Scheiber, R., Mittermayer, J., and Spielbauer, R. (1995, January 10\u201314). Real-time implementation of the extended chirp scaling algorithm for air- and spaceborne SAR-processing. Proceedings of the International Geoscience and Remote Sensing Symposium (IGARSS), Firenze, Italy."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1109\/LGRS.2017.2647962","article-title":"A New Distortion Correction Method for FMCW SAR Real-Time Imaging","volume":"14","author":"Gu","year":"2017","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1080\/01431169108929650","article-title":"A new approach to range-Doppler SAR processing","volume":"12","author":"Smith","year":"1991","journal-title":"Int. J. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"786","DOI":"10.1109\/36.298008","article-title":"Precision SAR processing using chirp scaling","volume":"32","author":"Keith","year":"1994","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1109\/7.78293","article-title":"SAR data focussing using seismic migration techniques","volume":"27","author":"Cafforio","year":"1991","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1433","DOI":"10.1109\/TAES.2008.4667720","article-title":"A polar format algorithm using chirp scaling for spotlight SAR image formation","volume":"44","author":"Zhu","year":"2008","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4761","DOI":"10.1109\/TGRS.2012.2230267","article-title":"Multichannel Full-Aperture Azimuth Processing for Beam Steering SAR","volume":"51","author":"Sun","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3139","DOI":"10.1109\/TGRS.2012.2212280","article-title":"A Unified Focusing Algorithm for Several Modes of SAR Based on FrFT","volume":"51","author":"Sun","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"604","DOI":"10.1109\/LGRS.2016.2530817","article-title":"Micro-Doppler Reconstruction in Spaceborne SAR Images Using Azimuth Time\u2013Frequency Tracking of the Phase History","volume":"13","author":"Anghel","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1425","DOI":"10.1109\/JSTARS.2016.2618518","article-title":"Improved Signal Reconstruction Algorithm for Multichannel SAR Based on the Doppler Spectrum Estimation","volume":"10","author":"Zuo","year":"2017","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1036","DOI":"10.1109\/LGRS.2011.2151174","article-title":"Sliding Spotlight and TOPS SAR Data Processing Without Subaperture","volume":"8","author":"Sun","year":"2011","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"714","DOI":"10.1109\/36.158865","article-title":"Real-time synthetic aperture radar (SAR) processing with a new subaperture approach","volume":"30","author":"Moreira","year":"1992","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"704","DOI":"10.1109\/LGRS.2018.2805311","article-title":"SAR Signal Recovery and Reconstruction in Staggered Mode with Low Oversampling Factors","volume":"15","author":"Wang","year":"2018","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1109\/LGRS.2017.2775043","article-title":"A chirp scaling algorithm for forward-looking linear-array SAR with constant acceleration","volume":"15","author":"Yuan","year":"2018","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_19","first-page":"1","article-title":"A frequency domain backprojection algorithm based on local cartesian coordinate and subregion range migration correction for high-squint SAR mounted on maneuvering platforms","volume":"99","author":"Bie","year":"2018","journal-title":"IEEE Trans. Geosci. Remote Sens."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/8\/2562\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:16:42Z","timestamp":1760195802000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/8\/2562"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,8,5]]},"references-count":19,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2018,8]]}},"alternative-id":["s18082562"],"URL":"https:\/\/doi.org\/10.3390\/s18082562","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,8,5]]}}}