{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,9]],"date-time":"2026-01-09T22:28:04Z","timestamp":1767997684221,"version":"3.49.0"},"reference-count":28,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2020,4,9]],"date-time":"2020-04-09T00:00:00Z","timestamp":1586390400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004837","name":"Ministerio de Ciencia e Innovaci\u00f3n","doi-asserted-by":"publisher","award":["RTI2018-099008-B-C21"],"award-info":[{"award-number":["RTI2018-099008-B-C21"]}],"id":[{"id":"10.13039\/501100004837","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Ag\u00e8ncia de Gesti\u00f3 d\u2019Ajuts Universitaris i de Recerca","award":["FI-DGR 2015"],"award-info":[{"award-number":["FI-DGR 2015"]}]},{"DOI":"10.13039\/501100011033","name":"Agencia Estatal de Investigaci\u00f3n","doi-asserted-by":"publisher","award":["MDM-2016-060"],"award-info":[{"award-number":["MDM-2016-060"]}],"id":[{"id":"10.13039\/501100011033","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>As opposed to monostatic radars where incoherent backscattering dominates, in bistatic radars, such as Global Navigation Satellite Systems Reflectometry (GNSS-R), the forward scattered signals exhibit both an incoherent and a coherent component. Current models assume that either one or the other are dominant, and the calibration and geophysical parameter retrieval (e.g., wind speed, soil moisture, etc.) are developed accordingly. Even the presence of the coherent component of a GNSS reflected signal itself has been a matter of discussion in the last years. In this work, a method developed to separate the leakage of the direct signal in the reflected one is applied to a data set of GNSS-R signals collected over the ocean by the Microwave Interferometer Reflectometer (MIR) instrument, an airborne dual-band (L1\/E1 and L5\/E5a), multi-constellation (GPS and Galileo) GNSS-R instrument with two 19-elements antenna arrays with 4 beam-steered each. The presented results demonstrate the feasibility of the proposed technique to untangle the coherent and incoherent components from the total power waveform in GNSS reflected signals. This technique allows the processing of these components separately, which increases the calibration accuracy (as today both are mixed and processed together), allowing higher resolution applications since the spatial resolution of the coherent component is determined by the size of the first Fresnel zone (300\u2013500 meters from a LEO satellite), and not by the size of the glistening zone (25 km from a LEO satellite). The identification of the coherent component enhances also the location of the specular reflection point by determining the peak maximum from this coherent component rather than the point of maximum derivative of the incoherent one, which is normally noisy and it is blurred by all the glistening zone contributions.<\/jats:p>","DOI":"10.3390\/rs12071208","type":"journal-article","created":{"date-parts":[[2020,4,9]],"date-time":"2020-04-09T14:42:03Z","timestamp":1586443323000},"page":"1208","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Untangling the Incoherent and Coherent Scattering Components in GNSS-R and Novel Applications"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6441-6676","authenticated-orcid":false,"given":"Joan Francesc","family":"Munoz-Martin","sequence":"first","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6636-1587","authenticated-orcid":false,"given":"Raul","family":"Onrubia","sequence":"additional","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8517-2415","authenticated-orcid":false,"given":"Daniel","family":"Pascual","sequence":"additional","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0031-0802","authenticated-orcid":false,"given":"Hyuk","family":"Park","sequence":"additional","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9514-4992","authenticated-orcid":false,"given":"Adriano","family":"Camps","sequence":"additional","affiliation":[{"name":"CommSensLab\u2014UPC, Universitat Polit\u00e8cnica de Catalunya\u2014BarcelonaTech, and IEEC\/CTE-UPC, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4375-4446","authenticated-orcid":false,"given":"Christoph","family":"R\u00fcdiger","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, Monash University, Clayton, VIC 3800, Australia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4817-2712","authenticated-orcid":false,"given":"Jeffrey","family":"Walker","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, Monash University, Clayton, VIC 3800, Australia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9186-6867","authenticated-orcid":false,"given":"Alessandra","family":"Monerris","sequence":"additional","affiliation":[{"name":"Department of Infrastructure Engineering, The University of Melbourne, Parkville, VIC 3010, Australia"}]}],"member":"1968","published-online":{"date-parts":[[2020,4,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6029","DOI":"10.1109\/TAP.2017.2752219","article-title":"The Transition From Weak to Strong Diffuse Radar Bistatic Scattering From Rough Ocean Surface","volume":"65","author":"Voronovich","year":"2017","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Carreno-Luengo, H., and Camps, A. (2016, January 10\u201315). Unified GNSS-R formulation including coherent and incoherent scattering components. Proceedings of the 2016 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China.","DOI":"10.1109\/IGARSS.2016.7730256"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1109\/LGRS.2019.2916164","article-title":"Spatial Resolution in GNSS-R Under Coherent Scattering","volume":"17","author":"Camps","year":"2020","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_4","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_5","doi-asserted-by":"crossref","first-page":"3198","DOI":"10.1109\/TGRS.2014.2371540","article-title":"Retrieval of Significant Wave Height and Mean Sea Surface Level Using the GNSS-R Interference Pattern Technique: Results From a Three-Month Field Campaign","volume":"53","author":"Camps","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1109\/TGRS.2010.2049023","article-title":"Land Geophysical Parameters Retrieval Using the Interference Pattern GNSS-R Technique","volume":"49","author":"Camps","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_7","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_8","doi-asserted-by":"crossref","first-page":"12065","DOI":"10.1029\/2019GL085134","article-title":"A CYGNSS-Based Algorithm for the Detection of Inland Waterbodies","volume":"46","author":"Ruf","year":"2019","journal-title":"Geophys. Res. Lett."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Onrubia, R., Pascual, D., Park, H., Camps, A., R\u00fcdiger, C., Walker, J., and Monerris, A. (2019). Satellite Cross-Talk Impact Analysis in Airborne Interferometric Global Navigation Satellite System-Reflectometry with the Microwave Interferometric Reflectometer. Remote Sens., 11.","DOI":"10.3390\/rs11091120"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Pascual, D., Onrubia, R., Alonso-Arroyo, A., Park, H., and Camps, A. (2014, January 13\u201318). The microwave interferometric reflectometer. Part II: Back-end and processor descriptions. Proceedings of the International Geoscience and Remote Sensing Symposium (IGARSS), Quebec City, QC, Canada.","DOI":"10.1109\/IGARSS.2014.6947307"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/j.asr.2010.02.002","article-title":"Advanced architectures for real-time Delay-Doppler Map GNSS-reflectometers: The GPS reflectometer instrument for PAU (griPAU)","volume":"46","author":"Valencia","year":"2010","journal-title":"Adv. Space Res."},{"key":"ref_12","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_13","unstructured":"Jales, P. (2012). Spaceborne Receiver Design for Scatterometric GNSS Reflectometry. [Ph.D. Thesis, University of Surrey]."},{"key":"ref_14","unstructured":"eoPortal Directory (2019, January 02). Cyclone GNSS Mission Description Website. Available online: https:\/\/directory.eoportal.org\/web\/eoportal\/satellite-missions\/c-missions\/cygnss."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Munoz-Martin, J.F., Fernandez, L., Ruiz-de-Azua, J., and Camps, A. (August, January 28). The Flexible Microwave Payload -2: A combined GNSS-R and L-band radiometer with RFI mitigation payload for CubeSat-based Earth Observation Missions. Proceedings of the 2019 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Yokohama, Japan.","DOI":"10.1109\/IGARSS.2019.8898402"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Khan, R., Khan, S.U., Zaheer, R., and Khan, S. (2011, January 11\u201313). Acquisition strategies of GNSS receiver. Proceedings of the International Conference on Computer Networks and Information Technology, Abbottabad, Pakistan.","DOI":"10.1109\/ICCNIT.2011.6020917"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1109\/LGRS.2014.2335772","article-title":"Mitigation of direct signal cross-talk and study of the coherent component in GNSS-R","volume":"12","author":"Martin","year":"2015","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1002","DOI":"10.1063\/1.325037","article-title":"Scattering of electromagnetic waves from a rough surface. II","volume":"49","author":"Holzer","year":"1978","journal-title":"J. Appl. Phys."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Foucras, M., Ekambi, B., Bacard, F., Julien, O., and Macabiau, C. (2014, January 5\u20138). Optimal GNSS acquisition parameters when considering bit transitions. Proceedings of the 2014 IEEE\/ION Position, Location and Navigation Symposium\u2014PLANS 2014, Monterey, CA, USA.","DOI":"10.1109\/PLANS.2014.6851445"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1436","DOI":"10.1109\/JSTARS.2014.2320873","article-title":"Optimization and performance analysis of interferometric GNSS-R altimeters: Application to the PARIS IoD mission","volume":"7","author":"Camps","year":"2014","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"7471","DOI":"10.3390\/rs70607471","article-title":"Empirical Results of a Surface-Level GNSS-R Experiment in a Wave Channel","volume":"7","author":"Camps","year":"2015","journal-title":"Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2112","DOI":"10.1109\/TGRS.2011.2172797","article-title":"Phase Altimetry With Dual Polarization GNSS-R Over Sea Ice","volume":"50","author":"Fabra","year":"2012","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Fabra, F., Cardellach, E., Ribo, S., Li, W., Rius, A., Arco-Fern\u00e1ndez, J., Nogu\u00e9s-Correig, O., Praks, J., Rouhe, E., and Sepp\u00e4nen, J. (2019). Is Accurate Synoptic Altimetry Achievable by Means of Interferometric GNSS-R?. Remote Sens., 11.","DOI":"10.3390\/rs11050505"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1007\/s10291-011-0251-7","article-title":"Retracking Considerations in Spaceborne GNSS-R Altimetry","volume":"16","author":"Park","year":"2012","journal-title":"GPS Solut."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"951","DOI":"10.1109\/36.841977","article-title":"Scattering of GPS signals from the ocean with wind remote sensing application","volume":"38","author":"Zavorotny","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2119","DOI":"10.1109\/TGRS.2009.2036721","article-title":"Altimetric analysis of the sea-surface GPS-reflected signals","volume":"48","author":"Rius","year":"2010","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_27","unstructured":"InMeteo (2020, January 07). Ventusky. Available online: https:\/\/ventusky.com."},{"key":"ref_28","unstructured":"U.S. Army Corps of Engineers (2012). Coastal Engineering Manual Part II: Coastal Hydrodynamics (EM 1110-2-1100)."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/7\/1208\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:16:50Z","timestamp":1760174210000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/7\/1208"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,4,9]]},"references-count":28,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2020,4]]}},"alternative-id":["rs12071208"],"URL":"https:\/\/doi.org\/10.3390\/rs12071208","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,4,9]]}}}