{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T00:03:17Z","timestamp":1783641797347,"version":"3.55.0"},"reference-count":33,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2015,12,21]],"date-time":"2015-12-21T00:00:00Z","timestamp":1450656000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Frequency modulated continuous wave (FMCW) technique has recently been employed by synthetic aperture radar (SAR) to decrease the radar cost and volume. However, the operation range is limited by the direct energy leakage from the transmitting channel to receiving channel due to the operation principle of FMCW technique. Bistatic configuration is an efficient way to increase the isolation between the transmitter and receiver, which could significantly increase the radar standoff range. A bistatic FMCW SAR spectrum model is proposed by using the Fresnel approximation in this paper. This model is similar to that of a monostatic FMCW SAR spectrum, which allows the existing imaging algorithms to be used on bistatic image processing. Based on the new model and the characteristics of FMCW signal, a modified range migration algorithm (RMA) for FMCW SAR is proposed to focus the image, which requires less memory and computational load than the traditional RMA. Point-target simulation is used to verify the proposed spectral model and real data processing verified the effectiveness of the proposed RMA.<\/jats:p>","DOI":"10.3390\/s151229910","type":"journal-article","created":{"date-parts":[[2015,12,21]],"date-time":"2015-12-21T10:43:59Z","timestamp":1450694639000},"page":"32123-32137","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Focusing Bistatic FMCW SAR Signal by Range Migration Algorithm Based on Fresnel Approximation"],"prefix":"10.3390","volume":"15","author":[{"given":"Yake","family":"Li","sequence":"first","affiliation":[{"name":"Faculty of Engineering and Applied Science, Memorial University of Newfoundland, 230 Elizabeth Avenue, St. John\u2019s, NL A1C5S7, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Siu","family":"O\u2019Young","sequence":"additional","affiliation":[{"name":"Faculty of Engineering and Applied Science, Memorial University of Newfoundland, 230 Elizabeth Avenue, St. John\u2019s, NL A1C5S7, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2015,12,21]]},"reference":[{"key":"ref_1","unstructured":"Edrich, M. (2004, January 11\u201315). Design Overview and Flight Test Results of the Miniaturised SAR Sensor MISAR. Proceedings of the First European Radar Conference 2004 EURAD, Amsterdam, The Netherlands."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1049\/ip-rsn:20045080","article-title":"Ultra-lightweight synthetic aperture radar based on a 35 GHz FMCW sensor concept and online raw data transmission","volume":"153","author":"Edrich","year":"2006","journal-title":"IEE Proc. Radar Sonar Navig."},{"key":"ref_3","unstructured":"Meta, A., Wit, J., and Hoogeboom, P. (2004, January 11\u201315). Development of a High Resolution Airborne Millimeter Wave FM-CW SAR. Proceedings of the First European Radar Conference 2004 EURAD, Amsterdam, The Netherlands."},{"key":"ref_4","unstructured":"Zaugg, E.C., Hudson, D.L., and Long, D.G. (August, January 31). The BYU uSAR: A Small, Student-Built SAR for UAV Operation. Proceedings of the IEEE International Conference on Geoscience and Remote Sensing Symposium (IGARSS), Denver, CO, USA."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3053","DOI":"10.1109\/TGRS.2008.2002576","article-title":"A Contrast-Based Algorithm for Synthetic Range-Profile Motion Compensation","volume":"46","author":"Berizzi","year":"2008","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","unstructured":"Essen, H., Stanko, S., Sommer, R., Johannes, W., Wahlen, A., Wilcke, J., and Hantscher, S. (2011, January 5\u20138). Millimetre Wave SAR for UAV Operation. Proceedings of the 2011 Asia-Pacific Microwave Conference, Melbourne, Australia."},{"key":"ref_7","unstructured":"Max, F., Wahlen, A., Peter, W., and Erich, M. (2014, January 3\u20135). Processing of MIRANDA35 FMCW-SAR Data using a Time-Domain Algorithm. Proceedings of the 10th European Conference on Synthetic Aperture Radar (EUSAR), Berlin, Germany."},{"key":"ref_8","unstructured":"Rossum, W.V., Otten, M., and Dorp, P.V. (2012, January 23\u201326). Multichannel FMCW SAR. Proceedings of the 9th European Conference on Synthetic Aperture Radar (EUSAR), Nuremberg, Germany."},{"key":"ref_9","unstructured":"Hermann, R., Marc-Michael, M., Michael, K., and Ralph, M. (1998, January 15\u201317). Experiences with an Experimental Car controlled by a 77 GHz Radar Sensor. Proceedings of the International Radar Symposium, Munich, Germany."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Edwards, M., Madsen, D., Stringham, C., Margulis, A., Wicks, B., and Long, D. (2008, January 7\u201311). MicroASAR: A Small, Robust LFM-CW SAR for Operation on UAVs and Small Aircraft. Proceedings of the IEEE International Geoscience and Remote Sensing Symposium(IGARSS), Boston, MA, USA.","DOI":"10.1109\/IGARSS.2008.4780142"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1049\/ip-f-2.1992.0048","article-title":"Linear FMCW radar techniques","volume":"139","author":"Stove","year":"1992","journal-title":"Proc. Inst. Electr. Eng. F\u2014Radar Signal Process."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"472","DOI":"10.1049\/iet-rsn.2011.0276","article-title":"Model and signal processing of bistatic frequency modulated continuous wave synthetic aperture radar","volume":"6","author":"Liu","year":"2013","journal-title":"IET Radar Sonar Navig."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2017","DOI":"10.1109\/TAES.2013.6558035","article-title":"Bistatic FMCW SAR Signal Model and Imaging Approach","volume":"49","author":"Liu","year":"2013","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2031","DOI":"10.1109\/TGRS.2004.835295","article-title":"Models and useful relations for bistatic SAR processing","volume":"42","author":"Loffeld","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1109\/LGRS.2005.856700","article-title":"Modified range-Doppler processing for FM-CW synthetic aperture radar","volume":"3","author":"Meta","year":"2006","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2216","DOI":"10.1109\/TGRS.2008.918015","article-title":"A two-Dimensional Spectrum Model for General Bistatic SAR","volume":"46","author":"Geng","year":"2008","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1109\/7.78293","article-title":"SAR data focusing using seismic migration techniques","volume":"27","author":"Cafforio","year":"1991","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_18","unstructured":"Rocca, F., Prati, C., and Monti-Guarnieri, A. (1989). New Algorithms for Processing of SAR Data, Eur. Space Center Contract Rep.. ESA Contract Report, ESRIN contract 7998\/88\/F\/FL(SC)."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1049\/ip-rsn:20045087","article-title":"Extended wavenumber-domain synthetic aperture radar focusing with integrated motion compensation","volume":"153","author":"Reigber","year":"2006","journal-title":"IET Radar Sonar Navig."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2109","DOI":"10.1109\/TGRS.2009.2034368","article-title":"Focus FMCW SAR Data Using the Wavenumber Domain Algorithm","volume":"48","author":"Wang","year":"2010","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_21","unstructured":"Carrara, W., Goodman, R., and Majewski, R. (1995). Synthetic Aperture Radar Fundamentals. Spotlight Synthetic Aperture Radar: Signal Processing Algorithms, Artech House."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1574","DOI":"10.1109\/JSEN.2011.2175216","article-title":"Wavenumber-Domain Autofocusing for Highly Squinted UAV SAR Imagery","volume":"51","author":"Zhang","year":"2012","journal-title":"IEEE Sens. J."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"5031","DOI":"10.1109\/TGRS.2013.2276112","article-title":"Robust Autofocusing Approach for Highly Squinted SAR Imagery Using the Extended Wavenumber Algorithm","volume":"51","author":"Xu","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","unstructured":"Skolnik, M. (1990). Radar Handbook, McGraw-Hill. [2nd ed.]."},{"key":"ref_25","unstructured":"Cumming, I.G., and Wong, F.H. (2005). Digital Processing of Synthetic Aperture Radar, Artech House."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3519","DOI":"10.1109\/TGRS.2007.906140","article-title":"Signal Processing for FMCW SAR","volume":"45","author":"Meta","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3600","DOI":"10.1109\/TGRS.2014.2380154","article-title":"Generalized Frequency Scaling and Backprojection for LFM-CW LFM-CW SAR Processing","volume":"53","author":"Zaugg","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_28","first-page":"33","article-title":"Efficient and Precise Processing for Squinted Spotlight SAR through a Modified Stolt Mapping","volume":"2007","author":"Vandewal","year":"2007","journal-title":"EURASIP J. Adv. Signal Process."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1811","DOI":"10.1109\/TGRS.2004.832242","article-title":"A time-domain raw signal Simulator for interferometric SAR","volume":"42","author":"Mori","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1109\/36.124221","article-title":"SARAS: A Synthetic Aperture Radar (SAR) Raw Signal Simulator","volume":"30","author":"Franceschetti","year":"1992","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1109\/LGRS.2010.2050675","article-title":"Fast Raw-Signal Simulation of Extended Scenes for Missile-Borne SAR With Constant Acceleration","volume":"8","author":"Deng","year":"2011","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2323","DOI":"10.1109\/TGRS.2006.873206","article-title":"SAR Sensor Trajectory Deviations: Fourier Domain Formulation and Extended Scene Simulation of Raw Signal","volume":"44","author":"Franceschetti","year":"2006","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2851","DOI":"10.1109\/TGRS.2006.875786","article-title":"Efficient simulation of airborne SAR raw data of extended scenes","volume":"44","author":"Franceschetti","year":"2006","journal-title":"IEEE Trans. Geosci. Remote Sens."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/12\/29910\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:54:25Z","timestamp":1760216065000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/12\/29910"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,12,21]]},"references-count":33,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2015,12]]}},"alternative-id":["s151229910"],"URL":"https:\/\/doi.org\/10.3390\/s151229910","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,12,21]]}}}