{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,25]],"date-time":"2026-02-25T17:58:38Z","timestamp":1772042318106,"version":"3.50.1"},"reference-count":9,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2024,4,11]],"date-time":"2024-04-11T00:00:00Z","timestamp":1712793600000},"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>Positioning a Synthetic Aperture Radar (SAR) receiver at a significant distance from an illuminator in a Low Earth Orbit (LEO) enables wide-angle repeat-pass bistatic interferometry. It\u2019s crucial to define the positioning limits of the receiver with respect to the illuminator to ensure reasonable coherences, altitudes of ambiguity, and a suitable common wavenumber support. I extended the standard monostatic formula, which yields the change in the interferometric travel path due to the vertical baseline. In the wide-angle bistatic case, the range-azimuth coordinate system is no longer orthogonal and we must consider the full 2D vector nature of the LOS orthogonal components. The two vertical baselines and the horizontal baseline of the receiver are needed to parameterize the system. Their impact on the interferometric coherence is quantified and bistatic limits are seen to be more flexible than those in the monostatic case due to the combination of independent baselines. I estimated the coherence, and then extended the analysis to the wavenumber domain, to quantify the common spectral support due to the wavenumber shifts due to the three baselines. The analysis carried out geometrically allows for combining together the effects of the transmitter\u2019s and receiver\u2019s vertical baselines and thus representing the residual spectral fraction with two instead of three parameters. Finally, I examined the achievable spatial resolution of the position of the interferer obtainable from the delay of the arrival of the interference between the illuminator (supposed to be silent) and the receiver.<\/jats:p>","DOI":"10.3390\/rs16081339","type":"journal-article","created":{"date-parts":[[2024,4,11]],"date-time":"2024-04-11T03:29:04Z","timestamp":1712806144000},"page":"1339","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Wide-Angle Repeat Pass Bistatic SAR Interferometry: A Geometrical Introduction"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2266-6212","authenticated-orcid":false,"given":"Fabio","family":"Rocca","sequence":"first","affiliation":[{"name":"Dipartimento di Elettronica, Informatica, Bioingegneria (DEIB), Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Wang, R., and Deng, Y. (2018). Bistatic SAR System and Signal Processing Technology, Springer.","DOI":"10.1007\/978-981-10-3078-9"},{"key":"ref_2","unstructured":"Krieger, G. (2023). Bistatic and Multistatic SAR: State of the Art and Future Developments, GRSS."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3317","DOI":"10.1109\/TGRS.2007.900693","article-title":"TanDEM-X: A Satellite Formation for High-Resolution SAR Interferometry","volume":"45","author":"Krieger","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1190\/1.1442237","article-title":"Diffraction tomography and multisource holography applied to seismic imaging","volume":"52","author":"Wu","year":"1987","journal-title":"Geophysics"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"855","DOI":"10.1109\/36.298013","article-title":"The wavenumber shift in SAR interferometry","volume":"32","author":"Gatelli","year":"1994","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","unstructured":"Rocca, F. (2024, April 02). 3D Motion Recovery with Multi-Angle and\/or Left Right Interferometry. Proceedings of the ESA Fringe 2003 Workshop. Available online: https:\/\/site.tre-altamira.com\/wp-content\/uploads\/2003_3D_motion_recovery_from_multiangle_and_or_left_right_interferometry.pdf."},{"key":"ref_7","unstructured":"Gebert, N., Carnicero Dominguez, B., Davidson, M.W.J., Diaz Martin, M., and Silvestrin, P. (2014, January 3\u20135). SAOCOM-CS\u2014A passive companion to SAOCOM for single-pass L-band SAR interferometry. Proceedings of the EUSAR 2014; 10th European Conference on Synthetic Aperture Radar, Berlin, Germany."},{"key":"ref_8","unstructured":"(2022, June 30). Harmony: Earth Explorer 10 Candidate Mission: Harmony Report for Mission Selection ESA\u2014EOPSM\u2014HARM-RP-4129 Issue\/Revision 1.1. Available online: https:\/\/esamultimedia.esa.int\/docs\/EarthObservation\/EE10_Harmony_Report-for-Selection_21June2022.pdf."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Theodosiou, A., and L\u00f3pez-Dekker, P. (2023, January 16\u201321). A Spectral Method of Calculating the Baselines of Bistatic SAR Interferometers. Proceedings of the IGARSS 2023\u20132023 IEEE International Geoscience and Remote Sensing Symposium, Pasadena, CA, USA.","DOI":"10.1109\/IGARSS52108.2023.10283110"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/8\/1339\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:26:07Z","timestamp":1760106367000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/8\/1339"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4,11]]},"references-count":9,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2024,4]]}},"alternative-id":["rs16081339"],"URL":"https:\/\/doi.org\/10.3390\/rs16081339","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4,11]]}}}