{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:47:48Z","timestamp":1760150868524,"version":"build-2065373602"},"reference-count":37,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,1,22]],"date-time":"2022-01-22T00:00:00Z","timestamp":1642809600000},"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>In this article, we present a link budget analysis for Global Navigation Satellite System (GNSS) signals scattered off the sea surface in arbitrary acquisition geometries. The aim of our study is to investigate the reliability of the Geometrical Optics (GO) scattering model, which accurately describes sea surface scattering at and near the specular reflection direction, in properly modeling the sea surface return in far-from-specular acquisition geometries, which are of interest for maritime surveillance purposes and where GO is expected to fail. To this end, we adopted the recent Bistatic Anisotropic Polarimetric Two-Scale Model (BA-PTSM), which revealed good agreement with advanced scattering models, such as the second-order Small Slope Approximation (SSA2), regardless of the acquisition geometry, with the advantage of a reduced computational complexity. Numerical results have been derived for both circular polarization channels and for both spaceborne and airborne GNSS-Reflectometry (GNSS-R). It has been shown that, as long as conventional GNSS-R processing is assumed, GO can be safely adopted for simulation and analysis of spaceborne GNSS-R data regardless of the acquisition geometry and sea state, whereas more accurate scattering models, e.g., BA-PTSM, should be used for airborne receivers in far-from-specular configurations.<\/jats:p>","DOI":"10.3390\/rs14030520","type":"journal-article","created":{"date-parts":[[2022,1,23]],"date-time":"2022-01-23T20:34:40Z","timestamp":1642970080000},"page":"520","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Link Budget Analysis for GNSS-R Sea Surface Return in Arbitrary Acquisition Geometries Using BA-PTSM"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4200-2584","authenticated-orcid":false,"given":"Gerardo","family":"Di Martino","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering and Information Technology, University of Napoli Federico II, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1374-1871","authenticated-orcid":false,"given":"Alessio","family":"Di Simone","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering and Information Technology, University of Napoli Federico II, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6173-3601","authenticated-orcid":false,"given":"Antonio","family":"Iodice","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering and Information Technology, University of Napoli Federico II, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5299-1692","authenticated-orcid":false,"given":"Daniele","family":"Riccio","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering and Information Technology, University of Napoli Federico II, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Hall, C., and Cordey, R. (1988, January 12\u201316). Multistatic Scatterometry. Proceedings of the International Geoscience and Remote Sensing Symposium, \u2018Remote Sensing: Moving Toward the 21st Century\u2019, Edinburgh, UK.","DOI":"10.1109\/IGARSS.1988.570200"},{"key":"ref_2","first-page":"331","article-title":"A passive reflectometry and interferometry system (PARIS): Application to ocean altimetry","volume":"17","year":"1993","journal-title":"ESA J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"5435","DOI":"10.1002\/2015GL064204","article-title":"Spaceborne GNSS reflectometry for ocean winds: First results from the UK TechDemoSat-1 mission","volume":"42","author":"Foti","year":"2015","journal-title":"Geophys. Res. Lett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"6829","DOI":"10.1109\/TGRS.2014.2303831","article-title":"Spaceborne GNSS-R minimum variance wind speed estimator","volume":"52","author":"Clarizia","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1522","DOI":"10.1109\/JSTARS.2014.2322854","article-title":"Airborne GNSS-R polarimetric measurements for soil moisture and above-ground biomass estimation","volume":"7","author":"Egido","year":"2014","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4322","DOI":"10.1109\/TGRS.2018.2890646","article-title":"Time-Series Retrieval of Soil Moisture Using CYGNSS","volume":"57","author":"Johnson","year":"2019","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4989","DOI":"10.1109\/TGRS.2017.2699122","article-title":"Sea Ice Detection Using U.K. TDS-1 GNSS-R Data","volume":"55","author":"Zavorotny","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Yan, Q., and Huang, W. (2019). Sea Ice Remote Sensing Using GNSS-R: A Review. Remote Sens., 11.","DOI":"10.3390\/rs11212565"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1109\/MGRS.2014.2374220","article-title":"Tutorial on remote sensing using GNSS bistatic radar of opportunity","volume":"2","author":"Zavorotny","year":"2014","journal-title":"IEEE Geosci. Remote Sens. Mag."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"13120","DOI":"10.3390\/rs71013120","article-title":"First Polarimetric GNSS-R Measurements from a Stratospheric Flight over Boreal Forests","volume":"7","author":"Vidal","year":"2015","journal-title":"Remote Sens."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Ricciardulli, L., Mears, C., Manaster, A., and Meissner, T. (2021). Assessment of CYGNSS Wind Speed Retrievals in Tropical Cyclones. Remote Sens., 13.","DOI":"10.3390\/rs13245110"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Pascual, D., Clarizia, M.P., and Ruf, C.S. (2021). Improved CYGNSS Wind Speed Retrieval Using Significant Wave Height Correction. Remote Sens., 13.","DOI":"10.3390\/rs13214313"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/TGRS.2020.3035989","article-title":"A Semiempirical Modeling of Soil Moisture, Vegetation, and Surface Roughness Impact on CYGNSS Reflectometry Data","volume":"60","author":"Yueh","year":"2022","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_14","first-page":"1","article-title":"Diurnal Variations in Ocean Wind Speeds Measured by CYGNSS and Other Satellites","volume":"19","author":"Yi","year":"2022","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_15","unstructured":"Carrie, G., Deloues, T., Mametsa, J., and Angelliaume, S. (2011). Ship Detection Based on GNSS Reflected Signals: An Experimental Plan, Proc. Space Reflecto."},{"key":"ref_16","unstructured":"Clarizia, M.P., Braca, P., Ruf, C.S., and Willett, P. (2015, January 6\u20139). Target detection using GPS signals of opportunity. Proceedings of the 2015 18th International Conference on Information Fusion (FUSION), Washington, DC, USA."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4237","DOI":"10.1109\/JSTARS.2017.2705350","article-title":"Sea Target Detection Using Spaceborne GNSS-R Delay-Doppler Maps: Theory and Experimental Proof of Concept Using TDS-1 Data","volume":"10","author":"Park","year":"2017","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1109\/MAES.2021.3070862","article-title":"Space-Based Global Maritime Surveillance. Part I: Satellite Technologies","volume":"36","author":"Soldi","year":"2021","journal-title":"IEEE Aerosp. Electron. Syst. Mag."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Di Simone, A., Braca, P., Millefiori, L.M., and Willett, P. (2018, January 23\u201327). Ship detection using GNSS-reflectometry in backscattering configuration. Proceedings of the 2018 IEEE Radar Conference (RadarConf18), Oklahoma City, OK, USA.","DOI":"10.1109\/RADAR.2018.8378804"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Di Simone, A., Millefiori, L.M., Di Martino, G., Iodice, A., Riccio, D., Ruello, G., Braca, P., and Willett, P. (2018, January 22\u201327). Spaceborne GNSS-Reflectometry for Ship-Detection Applications: Impact of Acquisition Geometry and Polarization. Proceedings of the IGARSS 2018-2018 IEEE International Geoscience and Remote Sensing Symposium, Valencia, Spain.","DOI":"10.1109\/IGARSS.2018.8518989"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1385","DOI":"10.1109\/JSTARS.2020.2970221","article-title":"Simulation-Based Feasibility Analysis of Ship Detection Using GNSS-R Delay-Doppler Maps","volume":"13","author":"Beltramonte","year":"2020","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Hu, C., Benson, C., Park, H., Camps, A., Qiao, L., and Rizos, C. (2019). Detecting Targets above the Earth\u2019s Surface Using GNSS-R Delay Doppler Maps: Results from TDS-1. Remote Sens., 11.","DOI":"10.3390\/rs11192327"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1109\/TGRS.2019.2941140","article-title":"Analytical Models for the Electromagnetic Scattering from Isolated Targets in Bistatic Configuration: Geometrical Optics Solution","volume":"58","author":"Fuscaldo","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1362","DOI":"10.1109\/TAP.2013.2295235","article-title":"Full-Polarization Modeling of Monostatic and Bistatic Radar Scattering from a Rough Sea Surface","volume":"62","author":"Voronovich","year":"2014","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3372","DOI":"10.1109\/TGRS.2007.897436","article-title":"Bistatic Radar Imaging of the Marine Environment\u2014Part I: Theoretical Background","volume":"45","author":"Khenchaf","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3656","DOI":"10.1109\/TGRS.2020.3021784","article-title":"Bistatic Scattering from Anisotropic Rough Surfaces via a Closed-Form Two-Scale Model","volume":"59","author":"Iodice","year":"2021","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Di Martino, G., Di Simone, A., Iodice, A., Riccio, D., and Ruello, G. (2021, January 11\u201316). Simulation of GNSS-R Signals in Arbitrary Viewing Geometry with a Closed-Form Bistatic Two-Scale Model. Proceedings of the 2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS, Brisbane, Australia.","DOI":"10.1109\/IGARSS47720.2021.9554743"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Di Martino, G., Di Simone, A., Franceschetti, G., Iodice, A., Riccio, D., and Ruello, G. (September, January 28). Link Budget Analysis for the Modeling of GNSS-R Sea Surface Returns in Far-from-Specular Acquisition Geometries. Proceedings of the 2021 XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Rome, Italy.","DOI":"10.23919\/URSIGASS51995.2021.9560646"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1057","DOI":"10.1002\/rds19683111057","article-title":"Scattering of electromagnetic waves from a tilted slightly rough surface","volume":"3","author":"Valenzuela","year":"1968","journal-title":"Radio Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1109\/TAP.1968.1139147","article-title":"A new model for sea clutter","volume":"16","author":"Wright","year":"1968","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_31","unstructured":"Ulaby, F., Moore, R., and Fung, A. (1981). Microwave Remote Sensing: Active and Passive, Artech House Remote Sensing Library, Addison-Wesley Publishing Company, Advanced Book Program\/World Science Division."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2531","DOI":"10.1109\/TGRS.2011.2106792","article-title":"Retrieval of Soil Surface Parameters via a Polarimetric Two-Scale Model","volume":"49","author":"Iodice","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"6182","DOI":"10.1109\/TGRS.2019.2904761","article-title":"Closed-Form Anisotropic Polarimetric Two-Scale Model for Fast Evaluation of Sea Surface Backscattering","volume":"57","author":"Iodice","year":"2019","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Katzberg, S.J., Torres, O., and Ganoe, G. (2006). Calibration of reflected GPS for tropical storm wind speed retrievals. Geophys. Res. Lett., 33.","DOI":"10.1029\/2006GL026825"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Cloude, S. (2009). Polarisation: Applications in Remote Sensing, OUP Oxford.","DOI":"10.1093\/acprof:oso\/9780199569731.001.0001"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"4525","DOI":"10.1109\/JSTARS.2016.2603846","article-title":"Spaceborne GNSS-Reflectometry on TechDemoSat-1: Early Mission Operations and Exploitation","volume":"9","author":"Unwin","year":"2016","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1109\/TGRS.2006.882257","article-title":"A GPS-Reflections Receiver That Computes Doppler\/Delay Maps in Real Time","volume":"45","author":"Rius","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/3\/520\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:05:50Z","timestamp":1760133950000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/3\/520"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,1,22]]},"references-count":37,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2022,2]]}},"alternative-id":["rs14030520"],"URL":"https:\/\/doi.org\/10.3390\/rs14030520","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2022,1,22]]}}}