{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T10:28:23Z","timestamp":1769423303736,"version":"3.49.0"},"reference-count":52,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2022,12,16]],"date-time":"2022-12-16T00:00:00Z","timestamp":1671148800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000844","name":"European Union and the European Space Agency under the project FRM4S6","doi-asserted-by":"publisher","award":["No. 4000129892\/20\/NL\/FF\/ab"],"award-info":[{"award-number":["No. 4000129892\/20\/NL\/FF\/ab"]}],"id":[{"id":"10.13039\/501100000844","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Satellite altimetry plays a key role in monitoring changes in sea level and climate change. The quality of satellite altimetry products is commonly ensured through dedicated calibration. One such calibration is with microwave transponders acting as ground reference point targets. It is common practice that satellite ranges between the transponder phase center and the satellite center of gravity (CoG) are compared against the true geometric ranges to determine bias. Transponder ranges are, however, realized by the two phase centers of the altimeter and the ground transponder. So, to make this comparison feasible, the space origin of the measured range is transferred from the altimeter phase center (APC) to the satellite CoG by applying a constant offset, usually referred to as \u201cCoG correction\u201d. Instead of a fixed \u201cCoG correction\u201d, this work introduces the actual vector between APC and CoG in space, by examining the satellite attitude. Thus, the observed and geometric distances to the transponder are both referred to the APC. The case of Jason-3 and Sentinel-6A Michael Freilich (Sentinel-6A MF) with two transponders on Crete (CDN1) and Gavdos (GVD1) islands is examined. At first, the attitude of Jason-3 is determined by its quaternions. Then, analysis reveals that the transponder bias is correlated with the Jason-3 satellite attitude. The revised calibration brings about bias changes which fluctuate from about \u22122 mm to 1 mm in range and from \u2212110\u03bcs to +110 \u03bcs in datation for Jason-3. Spectral analysis on the bias differences between the revised and conventional transponder calibrations reveals constituents with periods of 117, 39 and 23 days. Finally, the revised methodology on crossover calibrations over the GVD1 transponder results in an improvement between the mean bias of the ascending and descending orbits by 12% for Jason-3 and by 14% (preliminary) for Sentinel-6A MF.<\/jats:p>","DOI":"10.3390\/rs14246369","type":"journal-article","created":{"date-parts":[[2022,12,19]],"date-time":"2022-12-19T08:41:41Z","timestamp":1671439301000},"page":"6369","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Impact of Satellite Attitude on Altimetry Calibration with Microwave Transponders"],"prefix":"10.3390","volume":"14","author":[{"given":"Costas","family":"Kokolakis","sequence":"first","affiliation":[{"name":"Geodesy and Geomatics Engineering Laboratory, Technical University of Crete, GR-73100 Chania, Greece"},{"name":"Space Geomatica P.C., Xanthoudidou 10A, GR-73134 Chania, Greece"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0148-8063","authenticated-orcid":false,"given":"Dimitrios","family":"Piretzidis","sequence":"additional","affiliation":[{"name":"Space Geomatica P.C., Xanthoudidou 10A, GR-73134 Chania, Greece"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1037-7376","authenticated-orcid":false,"given":"Stelios P.","family":"Mertikas","sequence":"additional","affiliation":[{"name":"Geodesy and Geomatics Engineering Laboratory, Technical University of Crete, GR-73100 Chania, Greece"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1007\/BF01095160","article-title":"Monitoring sea level changes","volume":"31","author":"Gornitz","year":"1995","journal-title":"Clim. Chang."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3635","DOI":"10.1038\/ncomms4635","article-title":"Timescales for detecting a significant acceleration in sea level rise","volume":"5","author":"Haigh","year":"2014","journal-title":"Nat. Commun."},{"key":"ref_3","unstructured":"Carlowicz, M. (2015, August 26). Sea Level Rise Hits Home at NASA: Watching Water Rise Right Outside the Front Door, Available online: https:\/\/earthobservatory.nasa.gov\/features\/NASASeaLevel."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1431","DOI":"10.1175\/BAMS-D-13-00047.1","article-title":"The concept of essential climate variables in support of climate research, applications, and policy","volume":"95","author":"Bojinski","year":"2014","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1541","DOI":"10.1175\/BAMS-D-11-00254.1","article-title":"The ESA climate change initiative: Satellite data records for essential climate variables","volume":"94","author":"Hollmann","year":"2013","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1063","DOI":"10.1016\/j.crte.2006.05.015","article-title":"Satellite altimetry and ocean dynamics","volume":"338","author":"Fu","year":"2006","journal-title":"Comptes Rendus Geosci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1319","DOI":"10.1007\/s10712-019-09569-1","article-title":"Satellite altimetry measurements of sea level in the coastal zone","volume":"40","author":"Vignudelli","year":"2019","journal-title":"Surv. Geophys."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Calmant, S., Cr\u00e9taux, J.F., and R\u00e9my, F. (2016). Principles of radar satellite altimetry for application on inland waters. Microwave Remote Sensing of Land Surface, Elsevier.","DOI":"10.1016\/B978-1-78548-159-8.50004-9"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1002\/2016GL071485","article-title":"Surface elevation change and mass balance of Icelandic ice caps derived from swath mode CryoSat-2 altimetry","volume":"43","author":"Foresta","year":"2016","journal-title":"Geophys. Res. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"e2019JC015878","DOI":"10.1029\/2019JC015878","article-title":"Increasing the space\u2013time resolution of mapped sea surface height from altimetry","volume":"125","author":"Archer","year":"2020","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e2019GL086880","DOI":"10.1029\/2019GL086880","article-title":"Global wave height trends and variability from new multimission satellite altimeter products, reanalyses, and wave buoys","volume":"47","author":"Timmermans","year":"2020","journal-title":"Geophys. Res. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1080\/01490419.2012.718676","article-title":"Ku-band radar altimeter surface wind speed algorithm","volume":"35","author":"Abdalla","year":"2012","journal-title":"Mar. Geod."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"105423","DOI":"10.1016\/j.jastp.2020.105423","article-title":"Daily harmonics of ionospheric total electron content from satellite altimetry","volume":"209","author":"Ray","year":"2020","journal-title":"J. Atmos. Sol.-Terr. Phys."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Rose, S.K., Andersen, O.B., Passaro, M., Ludwigsen, C.A., and Schwatke, C. (2019). Arctic Ocean sea level record from the complete radar altimetry era: 1991\u20132018. Remote Sens., 11.","DOI":"10.3390\/rs11141672"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"611","DOI":"10.5194\/tc-13-611-2019","article-title":"Dynamic ocean topography of the northern Nordic seas: A comparison between satellite altimetry and ocean modeling","volume":"13","author":"Wekerle","year":"2019","journal-title":"Cryosphere"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1109\/TGRS.1986.289601","article-title":"Relative Vertical Positioning Using Ground-Level Transponders with the ERS-1 Altimeter","volume":"GE-24","author":"Powell","year":"1986","journal-title":"IEEE Trans. Geosci. Remote. Sens."},{"key":"ref_17","unstructured":"Willis, J., Bonnefond, P., Leuliette, E., Scharroo, R., and Donlon, C. (2019). Report of the Ocean Surface Topography Science Team Meeting, OSTST Technical Report."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Blo\u00dffeld, M., Zeitlh\u00f6fler, J., Rudenko, S., and Dettmering, D. (2020). Observation-based attitude realization for accurate jason satellite orbits and its impact on geodetic and altimetry results. Remote Sens., 12.","DOI":"10.3390\/rs12040682"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1515\/jag-2021-0052","article-title":"Effect of PCV and attitude on the precise orbit determination of Jason-3 satellite","volume":"16","author":"Li","year":"2022","journal-title":"J. Appl. Geod."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2837","DOI":"10.1029\/JC095iC03p02837","article-title":"Corrections for the effects of significant wave height and attitude on Geosat radar altimeter measurements","volume":"95","author":"Hayne","year":"1990","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"24941","DOI":"10.1029\/94JC01777","article-title":"The corrections for significant wave height and attitude effects in the TOPEX radar altimeter","volume":"99","author":"Hayne","year":"1994","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1080\/01490410490465210","article-title":"Improving the Jason-1 ground retracking to better account for attitude effects","volume":"27","author":"Amarouche","year":"2004","journal-title":"Mar. Geod."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1080\/01490419.2014.1000470","article-title":"Assessment of SARAL\/AltiKa wave height measurements relative to buoy, Jason-2, and Cryosat-2 data","volume":"38","author":"Sepulveda","year":"2015","journal-title":"Mar. Geod."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1399","DOI":"10.1109\/LGRS.2013.2293960","article-title":"Measuring the pitch of CryoSat-2 using the SAR mode of the SIRAL altimeter","volume":"11","author":"Galin","year":"2014","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1080\/01490419.2011.584834","article-title":"Absolute calibration in bass strait, Australia: TOPEX, Jason-1 and OSTM\/Jason-2","volume":"34","author":"Watson","year":"2011","journal-title":"Mar. Geod."},{"key":"ref_26","unstructured":"Cristea, E., and Moore, P. (2007). Altimeter bias determination using two years of transponder observations. Proc. Envisat Symp., 23\u201327."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1080\/01490419.2012.718239","article-title":"A new method of precise Jason-2 altimeter calibration using a microwave transponder","volume":"35","author":"Hausleitner","year":"2012","journal-title":"Mar. Geod."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Quartly, G.D., Rinne, E., Passaro, M., Andersen, O.B., Dinardo, S., Fleury, S., Guerreiro, K., Guillot, A., Hendricks, S., and Kurekin, A.A. (2018). Review of radar altimetry techniques over the Arctic ocean: Recent progress and future opportunities for sea level and sea ice research. The Cryosphere Discussions, European Geosciences Union.","DOI":"10.5194\/tc-2018-148"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Mertikas, S., Tripolitsiotis, A., Donlon, C., Mavrocordatos, C., F\u00e9m\u00e9nias, P., Borde, F., Frantzis, X., Kokolakis, C., Guinle, T., and Vergos, G. (2020). The ESA Permanent Facility for altimetry calibration: Monitoring performance of radar altimeters for Sentinel-3A, Sentinel-3B and Jason-3 using transponder and sea-surface calibrations with FRM standards. Remote Sens., 12.","DOI":"10.3390\/rs12162642"},{"key":"ref_30","unstructured":"Wei, G., Xiao-Yan, G., Xi-Yu, X., Liu, H.G., Chuan-Dong, X., and Yue-Heng, D. (2011, January 24\u201327). A transponder system dedicating for the on-orbit calibration of China\u2019s new-generation satellite altimeter and scatterometer. Proceedings of the 2011 IEEE CIE International Conference on Radar, Chengdu, China."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"10162","DOI":"10.1109\/JSTARS.2021.3111922","article-title":"In-orbit calibration and validation of HY-2B altimeter using an improved transponder","volume":"14","author":"Wang","year":"2021","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_32","unstructured":"Birks, A. (2000, January 16\u201320). Radar altimeter calibration using ground based transponders. Proceedings of the ERS-ENVISAT Symposium, Gothenburg, Sweden."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Mertikas, S.P., Donlon, C., F\u00e9m\u00e9nias, P., Mavrocordatos, C., Galanakis, D., Tripolitsiotis, A., Frantzis, X., Tziavos, I.N., Vergos, G., and Guinle, T. (2018). Fifteen years of Cal\/Val service to reference altimetry missions: Calibration of satellite altimetry at the Permanent Facilities in Gavdos and Crete, Greece. Remote Sens., 10.","DOI":"10.3390\/rs10101557"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1016\/B978-0-12-417011-7.00018-0","article-title":"Strategies for the laboratory and field deployment of ship-borne fiducial reference thermal infrared radiometers in support of satellite-derived sea surface temperature climate data records","volume":"Volume 47","author":"Donlon","year":"2014","journal-title":"Experimental Methods in the Physical Sciences"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Mertikas, S.P., Donlon, C., F\u00e9m\u00e9nias, P., Cullen, R., Galanakis, D., Frantzis, X., and Tripolitsiotis, A. (2019). Fiducial Reference Measurements for Satellite Altimetry Calibration: The Constituents. Fiducial Reference Measurements for Altimetry, Springer.","DOI":"10.1007\/1345_2019_56"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Mertikas, S., Partsinevelos, P., Tripolitsiotis, A., Kokolakis, C., Petrakis, G., and Frantzis, X. (2020). Validation of Sentinel-3 OLCI integrated water vapor products using regional GNSS measurements in crete, Greece. Remote Sens., 12.","DOI":"10.3390\/rs12162606"},{"key":"ref_37","unstructured":"Cerri, A.L., and Couhert, P.F. (2022). DORIS Satellites Models Implemented in POE Processing, Centre National d\u2019\u00e8tudes Spatiales. Technical Report: SALP-NT-BORD-OP-16137-CN."},{"key":"ref_38","first-page":"87-074","article-title":"TOPEX satellite yaw maneuvers","volume":"968","author":"Perrygo","year":"1987","journal-title":"IOC"},{"key":"ref_39","unstructured":"Zeitlh\u00f6fler, J. (2019). Nominal and observation-based attitude realization for precise orbit determination of the Jason satellites. [Master\u2019s Thesis, Technical University of Munich, Department of Civil, Geo and Environmental Engineering]."},{"key":"ref_40","unstructured":"Vallado, D.A. (2001). Fundamentals of Astrodynamics and Applications, Springer Science & Business Media."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1109\/TAP.1977.1141536","article-title":"The average impulse response of a rough surface and its applications","volume":"25","author":"Brown","year":"1977","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1589","DOI":"10.1016\/j.asr.2018.01.008","article-title":"CryoSat-2 range, datation and interferometer calibration with Svalbard transponder","volume":"62","author":"Fornari","year":"2018","journal-title":"Adv. Space Res."},{"key":"ref_43","unstructured":"Petit, G., and Luzum, B. (2010). IERS Technical Note No. 36, IERS Conventions (2010), International Earth Rotation and Reference Systems Service. Technical Report."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1017\/S1743921314005535","article-title":"The IERS Conventions (2010): Reference systems and new models","volume":"10","author":"Luzum","year":"2012","journal-title":"Proc. Int. Astron. Union"},{"key":"ref_45","unstructured":"Giulicchi, L. (2022). Sentinel-6 Michael Freilich POD Context, European Space Agency. Technical Report JC-TN-ESA-SY-0420."},{"key":"ref_46","unstructured":"Roinard, L.M.H. (2021). Jason-3 Validation and Cross Calibration Activities (Annual Report 2020), Collecte Localisation Satellites. Technical Report SALP-RP-MA-EA-23473-CLS."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"2458","DOI":"10.1016\/j.asr.2022.07.001","article-title":"Performance evaluation of the CDN1 altimetry Cal\/Val transponder to internal and external constituents of uncertainty","volume":"70","author":"Mertikas","year":"2022","journal-title":"Adv. Space Res."},{"key":"ref_48","unstructured":"EUMETSAT (2022). Jason-CS\/Sentinel-6 RO Level 1B Auxiliary Data Specification, EUMETSAT. Technical Report EUM\/LEO-JASCS\/SPE\/16\/882105."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1109\/TGRS.2013.2242082","article-title":"Using the interferometric capabilities of the ESA CryoSat-2 mission to improve the accuracy of sea ice freeboard retrievals","volume":"52","author":"Armitage","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"232","DOI":"10.3389\/fmars.2019.00232","article-title":"Global observations of fine-scale ocean surface topography with the Surface Water and Ocean Topography (SWOT) mission","volume":"6","author":"Morrow","year":"2019","journal-title":"Front. Mar. Sci."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2235","DOI":"10.5194\/tc-14-2235-2020","article-title":"The Copernicus Polar Ice and Snow Topography Altimeter (CRISTAL) high-priority candidate mission","volume":"14","author":"Kern","year":"2020","journal-title":"Cryosphere"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"194","DOI":"10.3389\/fmars.2019.00194","article-title":"Concept design of the \u201cGuanlan\u201d science mission: China\u2019s novel contribution to space oceanography","volume":"6","author":"Chen","year":"2019","journal-title":"Front. Mar. Sci."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/24\/6369\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:42:37Z","timestamp":1760146957000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/24\/6369"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,16]]},"references-count":52,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["rs14246369"],"URL":"https:\/\/doi.org\/10.3390\/rs14246369","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,16]]}}}