{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T15:28:39Z","timestamp":1772638119862,"version":"3.50.1"},"reference-count":91,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,5,1]],"date-time":"2021-05-01T00:00:00Z","timestamp":1619827200000},"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>During its science phase from 2002\u20132017, the low-low satellite-to-satellite tracking mission Gravity Field Recovery And Climate Experiment (GRACE) provided an insight into Earth\u2019s time-variable gravity (TVG). The unprecedented quality of gravity field solutions from GRACE sensor data improved the understanding of mass changes in Earth\u2019s system considerably. Monthly gravity field solutions as the main products of the GRACE mission, published by several analysis centers (ACs) from Europe, USA and China, became indispensable products for quantifying terrestrial water storage, ice sheet mass balance and sea level change. The successor mission GRACE Follow-On (GRACE-FO) was launched in May 2018 and proceeds observing Earth\u2019s TVG. The Institute of Geodesy (IfE) at Leibniz University Hannover (LUH) is one of the most recent ACs. The purpose of this article is to give a detailed insight into the gravity field recovery processing strategy applied at LUH; to compare the obtained gravity field results to the gravity field solutions of other established ACs; and to compare the GRACE-FO performance to that of the preceding GRACE mission in terms of post-fit residuals. We use the in-house-developed MATLAB-based GRACE-SIGMA software to compute unconstrained solutions based on the generalized orbit determination of 3 h arcs. K-band range-rates (KBRR) and kinematic orbits are used as (pseudo)-observations. A comparison of the obtained solutions to the results of the GRACE-FO Science Data System (SDS) and Combination Service for Time-variable Gravity Fields (COST-G) ACs, reveals a competitive quality of our solutions. While the spectral and spatial noise levels slightly differ, the signal content of the solutions is similar among all ACs. The carried out comparison of GRACE and GRACE-FO KBRR post-fit residuals highlights an improvement of the GRACE-FO K-band ranging system performance. The overall amplitude of GRACE-FO post-fit residuals is about three times smaller, compared to GRACE. GRACE-FO post-fit residuals show less systematics, compared to GRACE. Nevertheless, the power spectral density of GRACE-FO and GRACE post-fit residuals is dominated by similar spikes located at multiples of the orbital and daily frequencies. To our knowledge, the detailed origin of these spikes and their influence on the gravity field recovery quality were not addressed in any study so far and therefore deserve further attention in the future. Presented results are based on 29 monthly gravity field solutions from June 2018 until December 2020. The regularly updated LUH-GRACE-FO-2020 time series of monthly gravity field solutions can be found on the website of the International Centre for Global Earth Models (ICGEM) and in LUH\u2019s research data repository. These operationally published products complement the time series of the already established ACs and allow for a continuous and independent assessment of mass changes in Earth\u2019s system.<\/jats:p>","DOI":"10.3390\/rs13091766","type":"journal-article","created":{"date-parts":[[2021,5,1]],"date-time":"2021-05-01T21:35:39Z","timestamp":1619904939000},"page":"1766","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Earth\u2019s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6521-4999","authenticated-orcid":false,"given":"Igor","family":"Koch","sequence":"first","affiliation":[{"name":"Institut f\u00fcr Erdmessung, Leibniz Universit\u00e4t Hannover, 30167 Hannover, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8036-2076","authenticated-orcid":false,"given":"Mathias","family":"Duwe","sequence":"additional","affiliation":[{"name":"Institut f\u00fcr Erdmessung, Leibniz Universit\u00e4t Hannover, 30167 Hannover, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5369-6158","authenticated-orcid":false,"given":"Jakob","family":"Flury","sequence":"additional","affiliation":[{"name":"Institut f\u00fcr Erdmessung, Leibniz Universit\u00e4t Hannover, 30167 Hannover, Germany"}]},{"given":"Akbar","family":"Shabanloui","sequence":"additional","affiliation":[{"name":"Institut f\u00fcr Erdmessung, Leibniz Universit\u00e4t Hannover, 30167 Hannover, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Tapley, B.D., Bettadpur, S., Watkins, M., and Reigber, C. (2004). The Gravity Recovery and Climate Experiment: Mission Overview and Early Results. Geophys. Res. Lett., 31.","DOI":"10.1029\/2004GL019920"},{"key":"ref_2","first-page":"16","article-title":"Instrument of GRACE: GPS augments gravity measurements","volume":"14","author":"Dunn","year":"2003","journal-title":"GPS World"},{"key":"ref_3","first-page":"321","article-title":"Accelerometers for CHAMP, GRACE and GOCE space missions: Synergy and evolution","volume":"40","author":"Touboul","year":"1999","journal-title":"Boll. Geof. Teor. Appl."},{"key":"ref_4","unstructured":"Bettadpur, S. (2021, March 24). UTCSR Level-2 Processing Standards Document (For Level-2 Product Release 0006), (Rev. 5.0, 18 April 2018), GRACE 327\u2013742. Available online: ftp:\/\/isdcftp.gfz-potsdam.de\/grace\/DOCUMENTS\/Level-2\/."},{"key":"ref_5","unstructured":"Yuan, D.-N. (2021, March 24). JPL Level-2 Processing Standards Document, For Level-2 Product Release 06. Available online: ftp:\/\/isdcftp.gfz-potsdam.de\/grace\/DOCUMENTS\/Level-2\/."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Dahle, C., Murb\u00f6ck, M., Flechtner, F., Dobslaw, H., Michalak, G., Neumayer, K.H., Abrykosov, O., Reinhold, A., K\u00f6nig, R., and Sulzbach, R. (2019). The GFZ GRACE RL06 Monthly Gravity Field Time Series: Processing Details and Quality Assessment. Remote Sens., 11.","DOI":"10.3390\/rs11182116"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"9332","DOI":"10.1029\/2019JB017415","article-title":"ITSG-Grace2018: Overview and evaluation of a new GRACE-only gravity field time series","volume":"124","author":"Kvas","year":"2019","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1196","DOI":"10.1093\/gji\/ggw081","article-title":"AIUB-RL02: An improved time-series of monthly gravity fields from GRACE data","volume":"205","author":"Meyer","year":"2016","journal-title":"Geophys. J. Int."},{"key":"ref_9","unstructured":"Lemoine, J.-M., Biancale, R., Reinquin, F., Bourgogne, S., and G\u00e9gout, P. (2019). CNES\/GRGS RL04 Earth gravity field models, from GRACE and SLR data. GFZ Data Serv."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"6010","DOI":"10.1029\/2018JB016596","article-title":"An optimized short-arc approach: Methodology and application to develop refined time series of Tongji-Grace2018 GRACE monthly solutions","volume":"124","author":"Chen","year":"2019","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"9415","DOI":"10.1029\/2019JB017752","article-title":"A New Hybrid Processing Strategy to Improve Temporal Gravity Field Solution","volume":"124","author":"Zhou","year":"2019","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1016\/j.geog.2015.05.010","article-title":"Monthly gravity field recovery from GRACE orbits and K-band measurements using variational equations approach","volume":"6","author":"Wang","year":"2015","journal-title":"Geod. Geodyn."},{"key":"ref_13","unstructured":"Naeimi, M., Koch, I., Khami, A., and Flury, J. (2018, January 8\u201313). IfE monthly gravity field solutions using the variational equations. Presented at the EGU General Assembly 2018, Vienna, Austria."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Koch, I., Flury, J., Naeimi, M., and Shabanloui, A. (2020). LUH-GRACE2018: A New Time Series of Monthly Gravity Field Solutions from\nGRACE. International Association of Geodesy Symposia, Springer.","DOI":"10.1007\/1345_2020_92"},{"key":"ref_15","unstructured":"F\u00f6rste, C., Bruinsma, S., Rudenko, S., Abrikosov, O., Lemoine, J.-M., Marty, J.-C., Neumayer, K.H., and Biancale, R. (2015, January 12\u201317). A time-variable satellite-only gravity field model to d\/o 300 based on LAGEOS, GRACE and GOCE data from the collaboration of GFZ Potsdam and GRGS Toulouse. Presented at the EGU General Assembly 2015, Vienna, Austria."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6111","DOI":"10.1029\/2018JB015641","article-title":"Tongji-Grace02s and Tongji-Grace02k: High-Precision Static GRACE-Only Global Earth\u2019s Gravity Field Models Derived by Refined Data Processing Strategies","volume":"123","author":"Chen","year":"2018","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"99","DOI":"10.5194\/essd-13-99-2021","article-title":"GOCO06s\u2014A satellite-only global gravity field model","volume":"13","author":"Kvas","year":"2021","journal-title":"Earth Syst. Sci. Data"},{"key":"ref_18","unstructured":"Savchenko, R., and Bosch, W. (2012). EOT11a\u2014Empirical Ocean Tide Model from Multi-Mission Satellite Altimetry, Deutsches Geod\u00e4tisches Forschungsinstitut (DGFI). DGFI Report No. 89."},{"key":"ref_19","unstructured":"Carrere, L., Lyard, F., Cancet, M., and Guillot, A. (2015, January 12\u201317). FES 2014, a new tidal model on the global ocean with enhanced accuracy in shallow seas and in the Arctic region. Presented at the EGU General Assembly 2015, Vienna, Austria."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3704","DOI":"10.1002\/jgrc.20271","article-title":"Simulating high-frequency atmosphere-ocean mass variability for dealiasing of satellite gravity observations: AOD1B RL05","volume":"118","author":"Dobslaw","year":"2019","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1093\/gji\/ggx302","article-title":"A new high-resolution model of non-tidal atmosphere and ocean mass variability for de-aliasing of satellite gravity observations: AOD1B RL06","volume":"211","author":"Dobslaw","year":"2017","journal-title":"Geophys. J. Int."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1818","DOI":"10.1016\/j.asr.2014.07.004","article-title":"Improvement of the GRACE star camera data based on the revision of the combination method","volume":"54","author":"Bandikova","year":"2014","journal-title":"Adv. Space Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1597","DOI":"10.1016\/j.asr.2016.08.007","article-title":"The role of accelerometer data calibration within GRACE gravity field recovery: Results from ITSG-Grace2016","volume":"58","author":"Klinger","year":"2016","journal-title":"Adv. Space Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1016\/j.asr.2019.05.021","article-title":"GRACE accelerometer data transplant","volume":"64","author":"Bandikova","year":"2019","journal-title":"Adv. Space Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1038\/s41558-019-0456-2","article-title":"Contributions of GRACE to understanding climate change","volume":"9","author":"Tapley","year":"2019","journal-title":"Nat. Clim. Chang."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Syed, T.H., Famiglietti, J.S., Rodell, M., Chen, J., and Wilson, C.R. (2008). Analysis of terrestrial water storage changes from GRACE and GLDAS. Water Resour. Res., 44.","DOI":"10.1029\/2006WR005779"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Tiwari, V.M., Wahr, J., and Swenson, S. (2009). Dwindling groundwater resources in northern India, from satellite gravity observations. Geophys. Res. Lett., 36.","DOI":"10.1029\/2009GL039401"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Houborg, R., Rodell, M., Li, B., Reichle, R., and Zaitchik, B.F. (2012). Drought indicators based on model-assimilated Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage observations. Water Resour. Res., 48.","DOI":"10.1029\/2011WR011291"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2110","DOI":"10.1002\/wrcr.20192","article-title":"Evaluation of groundwater depletion in North China using the Gravity Recovery and Climate Experiment (GRACE) data and ground-based measurements","volume":"49","author":"Feng","year":"2013","journal-title":"Water Resour. Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5698","DOI":"10.1002\/2014WR015595","article-title":"Global-scale assessment of groundwater depletion and related groundwater abstractions: Combining hydrological modeling with information from well observations and GRACE satellites","volume":"50","author":"Schuh","year":"2014","journal-title":"Water Resour. Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"733","DOI":"10.1002\/2015JD023808","article-title":"Does GRACE see the terrestrial water cycle \u201cintensifying\u201d?","volume":"121","author":"Eicker","year":"2016","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1016\/j.gloplacha.2006.06.003","article-title":"Interannual variations of the mass balance of the Antarctica and Greenland ice sheets from GRACE","volume":"53","author":"Ramillien","year":"2006","journal-title":"Glob. Planet. Chang."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1958","DOI":"10.1126\/science.1129007","article-title":"Satellite Gravity Measurements Confirm Accelerated Melting of Greenland Ice Sheet","volume":"313","author":"Chen","year":"2006","journal-title":"Science"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Velicogna, I. (2009). Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE. Geophys. Res. Lett., 36.","DOI":"10.1029\/2009GL040222"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Schrama, E.J.O., and Wouters, B. (2011). Revisiting Greenland ice sheet mass loss observed by GRACE. J. Geophys. Res., 116.","DOI":"10.1029\/2009JB006847"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Cazenave, A., Champollion, N., Paul, F., and Benveniste, J. (2017). Greenland and Antarctica Ice Sheet Mass Changes and Effects on Global Sea Level. Integrative Study of the Mean Sea Level and Its Components, Springer.","DOI":"10.1007\/978-3-319-56490-6"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Chambers, D.P. (2006). Observing seasonal steric sea level variations with GRACE and satellite altimetry. J. Geophys. Res., 111.","DOI":"10.1029\/2005JC002914"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.gloplacha.2008.10.004","article-title":"Sea level budget over 2003\u20132008: A reevaluation from GRACE space gravimetry, satellite altimetry and Argo","volume":"65","author":"Cazenave","year":"2009","journal-title":"Glob. Planet. Chang."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Leuliette, E.W., and Miller, L. (2009). Closing the sea level rise budget with altimetry, Argo, and GRACE. Geophys. Res. Lett., 36.","DOI":"10.1029\/2008GL036010"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Landerer, F.W., Flechtner, F.M., Save, H., Webb, F.H., Bandikova, T., Bertiger, W.I., Bettadpur, S.V., Byun, S.H., Dahle, C., and Dobslaw, H. (2020). Extending the Global Mass Change Data Record: GRACE Follow-On Instrument and Science Data Performance. Geophys. Res. Lett., 47.","DOI":"10.1029\/2020GL088306"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1083","DOI":"10.1007\/s00190-012-0566-3","article-title":"Intersatellite laser ranging instrument for the GRACE follow-on mission","volume":"86","author":"Sheard","year":"2012","journal-title":"J. Geod."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Abich, K., Abramovici, A., Amparan, B., Baatzsch, A., Okihiro, B.B., Barr, D.C., Bize, M.P., Bogan, C., Braxmaier, C., and Burke, M.J. (2019). In-Orbit Performance of the GRACE Follow-on Laser Ranging Interferometer. Phys. Rev. Lett., 123.","DOI":"10.1103\/PhysRevLett.123.031101"},{"key":"ref_43","unstructured":"Wen, Y.H., Kruizinga, G., Paik, M., Landerer, F., Bertiger, W., Sakamura, C., Bandikova, T., and McCullough, C. (2021, March 24). Gravity Recovery and Climate Experiment Follow-On (GRACE-FO), Level-1 Data Product User Handbook, JPL D-56935 (URS270772). Available online: ftp:\/\/isdcftp.gfz-potsdam.de\/grace-fo\/DOCUMENTS\/Level-1\/."},{"key":"ref_44","unstructured":"McCullough, C.M., Harvey, N., Save, H., and Bandikova, T. (2021, March 24). Description of Calibrated GRACE-FO Accelerometer Data Products (ACT), Level-1 Product Version 04, JPL D-103863. Available online: ftp:\/\/isdcftp.gfz-potsdam.de\/grace-fo\/DOCUMENTS\/Level-1\/."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"J\u00e4ggi, A., Meyer, U., Lasser, M., Jenny, B., Lopez, T., Flechtner, F., Dahle, C., F\u00f6rste, C., Mayer-G\u00fcrr, T., and Kvas, A. (2020). International Combination Service for Time-Variable Gravity Fields (COST-G). International Association of Geodesy Symposia, Springer.","DOI":"10.5194\/egusphere-egu21-2416"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1313","DOI":"10.1007\/s00190-018-1123-5","article-title":"Combination of GRACE monthly gravity field solutions from different processing strategies","volume":"92","author":"Jean","year":"2018","journal-title":"J. Geod."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1645","DOI":"10.1007\/s00190-019-01274-6","article-title":"Combination of GRACE monthly gravity fields on the normal equation level","volume":"93","author":"Meyer","year":"2019","journal-title":"J. Geod."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Meyer, U., Lasser, M., J\u00e4ggi, A., Dahle, C., Flechtner, F., Kvas, A., Behzadpour, S., Mayer-G\u00fcrr, T., Lemoine, J.-M., and Koch, I. (2020). International Combination Service for Time-variable Gravity Fields (COST-G) Monthly GRACE-FO Series. V. 01. GFZ Data Serv.","DOI":"10.5194\/gstm2020-16"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Heiskanen, W.A., and Moritz, H. (1967). Physical Geodesy, W. H. Freeman and Company.","DOI":"10.1007\/BF02525647"},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Torge, W., and M\u00fcller, J. (2012). Geodesy, Walter de Gruyter. [4th ed.].","DOI":"10.1515\/9783110250008"},{"key":"ref_51","unstructured":"Petit, G., and Luzum, B. (2010). IERS Conventions (2010), IERS Technical Note No. 36, Verlag des Bundesamts f\u00fcr Kartographie."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Seeber, G. (2003). Satellite Geodesy, Walter de Gruyter. [2nd ed.].","DOI":"10.1515\/9783110200089"},{"key":"ref_53","unstructured":"Montenbruck, O., and Gill, E. (2005). Satellite Orbits\u2014Models, Methods and Applications, Springer. [3rd ed.]."},{"key":"ref_54","unstructured":"Folkner, W.M., Williams, J.G., Boggs, D.H., Park, R.S., and Kuchynka, P. (2021, March 24). The Planetary and Lunar Ephemerides DE430 and DE431, IPN Progress Report 42-196, Available online: https:\/\/ipnpr.jpl.nasa.gov\/progress_report\/42-196\/196C.pdf."},{"key":"ref_55","unstructured":"Mayer-G\u00fcrr, T., and Kvas, A. (2021, March 24). COST-G Software Comparison, FES2014b Admittance. Available online: ftp:\/\/ftp.tugraz.at\/outgoing\/ITSG\/COST-G\/softwareComparison\/models\/FES2014b_oceanTide\/admittance\/."},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Desai, S.D. (2002). Observing the pole tide with satellite altimetry. J. Geophys. Res. Oceans, 107.","DOI":"10.1029\/2001JC001224"},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Behzadpour, S., Mayer-G\u00fcrr, T., and Krauss, S. (2021). GRACE Follow-On accelerometer data recovery. J. Geophys. Res. Solid Earth.","DOI":"10.1002\/essoar.10504698.1"},{"key":"ref_58","unstructured":"Naeimi, M. (2018, January 8\u201313). A modified Gauss-Jackson method for the numerical integration of the variational equations. Presented at the EGU General Assembly 2018, Vienna, Austria."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1","DOI":"10.5194\/adgeo-55-1-2020","article-title":"Benchmark data for verifying background model implementations in orbit and gravity field determination software","volume":"55","author":"Lasser","year":"2020","journal-title":"Adv. Geosci."},{"key":"ref_60","doi-asserted-by":"crossref","unstructured":"Naeimi, M., and Flury, J. (2017). Parameter Estimation for Satellite Gravity Field Modeling. Global Gravity Field Modeling from Satellite-to-Satellite Tracking Data, Springer.","DOI":"10.1007\/978-3-319-49941-3"},{"key":"ref_61","unstructured":"Kim, J. (2000). Simulation Study of A Low-Low Satellite-to-Satellite Tracking Mission. [Ph.D. Thesis, The University of Texas at Austin]."},{"key":"ref_62","unstructured":"Physical Oceanography Distributed Active Archive Center (PO.DAAC) (2021, March 24). GRACE-FO Level-1B Release Version 4.0 from JPL in ASCII, Available online: https:\/\/podaac-tools.jpl.nasa.gov\/drive\/files\/allData\/gracefo\/L1B\/JPL\/RL04\/ASCII."},{"key":"ref_63","unstructured":"Information System and Data Center (ISDC) (2019). GRACE-FO Gravity Data and Documentation. GFZ German Research Centre for Geosciences, Helmholtz Centre. Available online: ftp:\/\/isdcftp.gfz-potsdam.de\/grace-fo\/."},{"key":"ref_64","unstructured":"Arnold, D., and J\u00e4ggi, A. (2020). AIUB GRACE-FO Kinematic Orbits, Astronomical Institute, University of Bern. Available online: http:\/\/www.aiub.unibe.ch\/download\/LEO_ORBITS\/GRACE-FO."},{"key":"ref_65","unstructured":"GRACE-FO (2021, March 24). GRACEFO_L2_CSR_MONTHLY_0060. Ver. 6. PO.DAAC, CA, USA, Available online: https:\/\/podaac.jpl.nasa.gov\/dataset\/GRACEFO_L2_CSR_MONTHLY_0060."},{"key":"ref_66","unstructured":"Save, H. (2021, March 24). CSR Level-2 Processing Standards Document for Level-2 Product Release 06, CSR GRFO-19-01, (GRACE-FO D-103920). Available online: ftp:\/\/isdcftp.gfz-potsdam.de\/grace-fo\/DOCUMENTS\/Level-2\/."},{"key":"ref_67","unstructured":"Dahle, C., Flechtner, F., Murb\u00f6ck, M., Michalak, G., Neumayer, K.H., Abrykosov, O., Reinhold, A., and K\u00f6nig, R. (2021, March 24). GRACE-FO Geopotential GSM Coefficients GFZ RL06. V. 6.0. GFZ Data Services. Available online: https:\/\/dataservices.gfz-potsdam.de\/gravis\/showshort.php?id=escidoc:4289898."},{"key":"ref_68","unstructured":"Dahle, C., Flechtner, F., Murb\u00f6ck, M., Michalak, G., Neumayer, H., Abrykosov, O., Reinhold, A., and K\u00f6nig, R. (2021, March 24). GRACE-FO D-103919 (Gravity Recovery and Climate Experiment Follow-On), GFZ Level-2 Processing Standards Document for Level-2 Product Release 06 (Rev. 1.0, 3 June 2019), (Scientific Technical Report STR-Data; 19\/09). Available online: ftp:\/\/isdcftp.gfz-potsdam.de\/grace-fo\/DOCUMENTS\/Level-2\/."},{"key":"ref_69","unstructured":"GRACE-FO (2021, March 24). GRACEFO_L2_JPL_MONTHLY_0060. Ver. 6. PO.DAAC, CA, USA, Available online: https:\/\/podaac.jpl.nasa.gov\/dataset\/GRACEFO_L2_JPL_MONTHLY_0060."},{"key":"ref_70","unstructured":"Mayer-G\u00fcrr, T., Behzadpour, S., Kvas, A., and Strasser, S. (2021, March 24). ITSG-Gracefo2018\u2014Monthly, Daily and Static Gravity Field Solutions from GRACE-FO. GFZ Data Services. Available online: https:\/\/dataservices.gfz-potsdam.de\/icgem\/showshort.php?id=escidoc:3600910."},{"key":"ref_71","unstructured":"Lasser, M., Meyer, U., Arnold, D., and J\u00e4ggi, A. (2021, March 24). AIUB-GRACE-FO-Operational\u2014Operational GRACE Follow-On Monthly Gravity Field Solutions. GFZ Data Services. Available online: https:\/\/dataservices.gfz-potsdam.de\/icgem\/showshort.php?id=4c95fc04-fd9d-11ea-9603-497c92695674."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"647","DOI":"10.5194\/essd-11-647-2019","article-title":"ICGEM\u201415 years of successful collection and distribution of global gravitational models, associated services and future plans","volume":"11","author":"Ince","year":"2019","journal-title":"Earth Syst. Sci. Data"},{"key":"ref_73","doi-asserted-by":"crossref","unstructured":"Loomis, B.D., Rachlin, K.E., Wiese, D.N., Landerer, F.W., and Luthcke, S.B. (2020). Replacing GRACE\/GRACE-FO C30 With Satellite Laser Ranging: Impacts on Antarctic Ice Sheet Mass Change. Geophys. Res. Lett., 47.","DOI":"10.1029\/2019GL085488"},{"key":"ref_74","unstructured":"Loomis, B.D., and Rachlin, K.E. (2021, March 24). TN-14_C30_C20_SLR_GSFC, NASA GSFC SLR C20 and C30 Solutions. Available online: ftp:\/\/isdcftp.gfz-potsdam.de\/grace-fo\/DOCUMENTS\/TECHNICAL_NOTES."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1007\/s00190-010-0401-7","article-title":"The celestial mechanics approach: Theoretical foundations","volume":"84","author":"Beutler","year":"2010","journal-title":"J. Geod."},{"key":"ref_76","unstructured":"Ellmer, M. (2018). Contributions to GRACE Gravity Field Recovery: Improvements in Dynamic Orbit Integration Stochastic Modelling of the Antenna Offset Correction, and Co-Estimation of Satellite Orientations. [Ph.D. Thesis, Graz University of Technology]."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"30205","DOI":"10.1029\/98JB02844","article-title":"Time variability of the Earth\u2019s gravity field: Hydrological and oceanic effects and their possible detection using GRACE","volume":"103","author":"Wahr","year":"1998","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_78","doi-asserted-by":"crossref","unstructured":"Swenson, S., and Wahr, J. (2002). Methods for inferring regional surface-mass anomalies from Gravity Recovery and Climate Experiment (GRACE) measurements of time-variable gravity. J. Geophys. Res. Solid Earth, 107.","DOI":"10.1029\/2001JB000576"},{"key":"ref_79","doi-asserted-by":"crossref","unstructured":"Oki, T., and Sud, Y.C. (1998). Design of Total Runoff Integrating Pathways (TRIP)\u2014A Global River Channel Network. Earth Interact., 2.","DOI":"10.1175\/1087-3562(1998)002<0001:DOTRIP>2.3.CO;2"},{"key":"ref_80","unstructured":"Total Runoff Integrating Pathways (TRIP) (2021, March 24). Vector Files of Major River Basin Boundaries, Corresponding to TRIP Version 22 May 1997. Available online: http:\/\/hydro.iis.u-tokyo.ac.jp\/~taikan\/TRIPDATA\/Data\/RBvect.html."},{"key":"ref_81","unstructured":"Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) (2021, March 24). Antarctica and Greenland Ice Sheet Drainage Basins. Available online: http:\/\/imbie.org\/wp-content\/uploads\/2016\/09\/GRE_Basins_IMBIE2_v1.3.zip."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"197","DOI":"10.5194\/gi-8-197-2019","article-title":"Multiresolution wavelet analysis applied to GRACE range rate residuals","volume":"8","author":"Behzadpour","year":"2019","journal-title":"Geosci. Instrum. Method. Data Syst."},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1016\/j.asr.2018.04.036","article-title":"Analysis of GRACE range-rate residuals with focus on KBR instrument system noise","volume":"62","author":"Goswami","year":"2018","journal-title":"Adv. Space Res."},{"key":"ref_84","doi-asserted-by":"crossref","unstructured":"Harvey, N., Dunn, C.E., Kruizinga, G.L., and Young, L.E. (2017). Triggering Conditions for GRACE Ranging Measurement Signal-to-Noise Ratio Dips. J. Spacecr. Rockets, 54.","DOI":"10.2514\/1.A33578"},{"key":"ref_85","unstructured":"International Centre for Global Earth Models (ICGEM) (2021, March 24). LUH\/LUH-GRACE-FO-2020. Available online: http:\/\/icgem.gfzpotsdam.de\/series\/10.25835\/0062546."},{"key":"ref_86","unstructured":"Koch, I., Duwe, M., Flury, J., and Shabanloui, A. (2021, March 24). Dataset: LUH-GRACE-FO-2020. Available online: https:\/\/data.uni-hannover.de\/dataset\/luh-grace-fo-2020."},{"key":"ref_87","unstructured":"Koch, K.-R. (2013). Parameter Estimation and Hypothesis Testing in Linear Models, Springer. [2nd ed.]."},{"key":"ref_88","doi-asserted-by":"crossref","unstructured":"Niemeier, W. (2008). Ausgleichungsrechnung: Statistische Auswertemethoden, Walter de Gruyter. [2nd ed.].","DOI":"10.1515\/9783110206784"},{"key":"ref_89","doi-asserted-by":"crossref","unstructured":"Naeimi, M., and Flury, J. (2017). Precise Orbit Determination. Global Gravity Field Modeling from Satellite-to-Satellite Tracking Data, Springer.","DOI":"10.1007\/978-3-319-49941-3"},{"key":"ref_90","unstructured":"Rummel, R., Reigber, C., and Ilk, K.-H. (1978, January 16-21). The use of satellite to satellite tracking for gravity parameter recovery. Proceedings of the European Workshop on Space Oceanography, Navigation and Geodynamics (SONG), Schloss Elmau, Germany. ESA SP-137."},{"key":"ref_91","unstructured":"Vallado, D.A. (2004). Fundamentals of Astrodynamics and Applications, Kluwer Academic Publishers. [2nd ed.]."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/9\/1766\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:56:32Z","timestamp":1760162192000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/9\/1766"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,1]]},"references-count":91,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2021,5]]}},"alternative-id":["rs13091766"],"URL":"https:\/\/doi.org\/10.3390\/rs13091766","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,1]]}}}