{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:13:49Z","timestamp":1760242429965,"version":"build-2065373602"},"reference-count":21,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2017,7,6]],"date-time":"2017-07-06T00:00:00Z","timestamp":1499299200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000844","name":"European Space Agency","doi-asserted-by":"publisher","award":["GEROS-ISS Phase A"],"award-info":[{"award-number":["GEROS-ISS Phase A"]}],"id":[{"id":"10.13039\/501100000844","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003329","name":"Ministerio de Econom\u00eda y Competitividad","doi-asserted-by":"publisher","award":["ESP2015-70014-C2-1-R"],"award-info":[{"award-number":["ESP2015-70014-C2-1-R"]}],"id":[{"id":"10.13039\/501100003329","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Seventh Framework Programme","award":["FP7-607126-E-GEM"],"award-info":[{"award-number":["FP7-607126-E-GEM"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The GEROS-ISS (GNSS rEflectometry, Radio Occultation and Scatterometry onboard International Space Station) is an innovative experiment for climate research, proposed in 2011 within a call of the European Space Agency (ESA). This proposal was the only one selected for further studies by ESA out of ~25 ones that were submitted. In this work, the instrument performance for the near-nadir altimetry (GNSS-R) mode is assessed, including the effects of multi-path in the ISS structure, the electromagnetic-bias, and the orbital height decay. In the absence of ionospheric scintillations, the altimetry rms error is &lt;50 cm for a swath &lt;~250 km and for U10 &lt;10 m\/s. If the transmitted power is 3 dB higher (likely to happen at beginning of life of the GNSS spacecrafts), mission requirements (rms error is &lt;50 cm) are met for all ISS heights and for U10 up to 15 m\/s. However, around 1.5 GHz, the ionosphere can induce significant fading, from 2 to &gt;20 dB at equatorial regions, mainly after sunset, which will seriously degrade the altimetry and the scatterometry performances of the instrument.<\/jats:p>","DOI":"10.3390\/s17071583","type":"journal-article","created":{"date-parts":[[2017,7,6]],"date-time":"2017-07-06T10:55:45Z","timestamp":1499338545000},"page":"1583","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["GNSS-R Altimetry Performance Analysis for the GEROS Experiment on Board the International Space Station"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9514-4992","authenticated-orcid":false,"given":"Adriano","family":"Camps","sequence":"first","affiliation":[{"name":"CommSensLab, Unidad de Excelencia Mar\u00eda de Maeztu, Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya, E-08034 Barcelona, Spain"},{"name":"Institut d\u2019Estudis Espacial de Catalunya\/Centre de Tecnologies Espacials-Universitat Polit\u00e8cnica de Catalunya, UPC Campus Nord, E-08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0031-0802","authenticated-orcid":false,"given":"Hyuk","family":"Park","sequence":"additional","affiliation":[{"name":"CommSensLab, Unidad de Excelencia Mar\u00eda de Maeztu, Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya, E-08034 Barcelona, Spain"},{"name":"Institut d\u2019Estudis Espacial de Catalunya\/Centre de Tecnologies Espacials-Universitat Polit\u00e8cnica de Catalunya, UPC Campus Nord, E-08034 Barcelona, Spain"}]},{"given":"Ivan","family":"Sekulic","sequence":"additional","affiliation":[{"name":"CommSensLab, Unidad de Excelencia Mar\u00eda de Maeztu, Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya, E-08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0606-5422","authenticated-orcid":false,"given":"Juan","family":"Rius","sequence":"additional","affiliation":[{"name":"CommSensLab, Unidad de Excelencia Mar\u00eda de Maeztu, Department of Signal Theory and Communications, Universitat Polit\u00e8cnica de Catalunya, E-08034 Barcelona, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2017,7,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4552","DOI":"10.1109\/JSTARS.2016.2614428","article-title":"GEROS-ISS: GNSS REflectometry, Radio Occultation, and Scatterometry Onboard the International Space Station","volume":"9","author":"Wickert","year":"2016","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_2","unstructured":"GNSS Reflectometry, Radio Occultation and Scatterometry onboard ISS (GEROS-ISS)\u2014SYSTEM REQUIREMENTS DOCUMENT, GEROS ESA Team, Ref. TEC-ETP\/2013.202\/MMN, Issue 1.1, rev. 0, date: 22\/01\/2014."},{"key":"ref_3","unstructured":"Kay, S.M. (1993). Fundamentals of Statistical Signal Processing: Estimation Theory, Prentice Hall."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Camps, A., Martin, F., Park, H., Valencia, E., Rius, A., and D\u2019Addio, S. (2012, January 22\u201327). Interferometric GNSS-R achievable altimetric performance and compression\/denoising using the wavelet transform: An experimental study. Proceedings of the 2012 IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2012), Munich, Germany.","DOI":"10.1109\/IGARSS.2012.6351894"},{"key":"ref_5","unstructured":"Camps\n              A.\n            \n            \n              Pascual\n              D.\n            \n            \n              Park\n              H.\n            \n            \n              Martin\n              F.\n            \n          \n        \n\t\t  PARIS IOD: ID-16A Contribution to Performance and Error Budgets Report, PARIS-PhA-IEEC-UPC-TN-008, v3.0, 14\/11\/2012."},{"key":"ref_6","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_7","unstructured":"Tress, H.L.V. (1971). Detection, Estimation and Modulation Theory, Part III: Radar-Sonar, Signal Processing and Gaussian Signals in Noise, Wiley. Chapter 10."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1416","DOI":"10.1109\/JSTARS.2014.2303251","article-title":"Precision Bounds in GNSS-R Ocean Altimetry","volume":"7","author":"Pascual","year":"2014","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2209","DOI":"10.1109\/TGRS.2010.2092431","article-title":"The PARIS Ocean altimeter","volume":"49","author":"Buck","year":"2011","journal-title":"IEEE Trans. Geosci. Remote. Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"7641","DOI":"10.1029\/1998JC900128","article-title":"Weakly nonlinear theory and sea state bias estimations","volume":"104","author":"Elfouhaily","year":"1999","journal-title":"J. Geophys. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1109\/TGRS.2015.2460212","article-title":"Numerical Computation of the Electromagnetic Bias in GNSS-R Altimetry","volume":"54","author":"Ghavidel","year":"2016","journal-title":"IEEE Trans. Geosci. Remote. Sens."},{"key":"ref_12","unstructured":"(2017, July 04). P.531: Ionospheric Propagation Data and Prediction Methods Required for the Design of Satellite Services and Systems. Available online: https:\/\/www.itu.int\/rec\/R-REC-P.531\/en."},{"key":"ref_13","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_14","doi-asserted-by":"crossref","unstructured":"Li, W., Rius, A., Fabra, F., Mart\u00edn-Neira, M., Cardellach, E., Rib\u00f3, S., and Yang, D. (2016). The Impact of Inter-Modulation Components on Interferometric GNSS-Reflectometry. Remote Sens., 8.","DOI":"10.3390\/rs8121013"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1481","DOI":"10.1109\/JSTARS.2014.2322198","article-title":"Analysis of Spaceborne GNSS-R Delay-Doppler Tracking","volume":"7","author":"Park","year":"2014","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_16","unstructured":"(2017, July 05). ISS (High Res), Available online: https:\/\/nasa3d.arc.nasa.gov\/detail\/iss-hi-res."},{"key":"ref_17","unstructured":"(2017, May 10). newFASANT: Simulation Software for Electromagnetic Field Analysis. Available online: https:\/\/www.fasant.com\/en."},{"key":"ref_18","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_19","unstructured":"(2017, July 05). Navstar GPS Space Segment\/Navigation User Interfaces, Available online: www.gps.gov\/technical\/icwg\/IS-GPS-200G.pdf."},{"key":"ref_20","unstructured":"(2017, July 05). Galileo Open Service SIS ICD: New Version 1.2. Available online: https:\/\/www.gsc-europa.eu\/system\/files\/galileo_documents\/Galileo-OS-SIS-ICD.pdf."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Onrubia, R., Querol, J., Pascual, D., Park, H., Alonso-Arroyo, A., and Camps, A. (2016, January 10\u201315). Assessment of DME\/TACAN RFI mitigation techniques in GNSS-R. Proceedings of the 2016 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China.","DOI":"10.1109\/IGARSS.2016.7730255"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/7\/1583\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:41:48Z","timestamp":1760208108000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/7\/1583"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,7,6]]},"references-count":21,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2017,7]]}},"alternative-id":["s17071583"],"URL":"https:\/\/doi.org\/10.3390\/s17071583","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2017,7,6]]}}}