{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,3]],"date-time":"2026-08-03T15:50:09Z","timestamp":1785772209213,"version":"3.56.0"},"reference-count":25,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2020,11,7]],"date-time":"2020-11-07T00:00:00Z","timestamp":1604707200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000104","name":"National Aeronautics and Space Administration","doi-asserted-by":"publisher","award":["80NSSC17K0410"],"award-info":[{"award-number":["80NSSC17K0410"]}],"id":[{"id":"10.13039\/100000104","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The Ice, Cloud and Land Elevation Satellite-2 (ICESat-2), an Earth-observing laser altimetry mission, is currently providing global elevation measurements. Geolocation validation confirms the altimeter\u2019s ability to accurately position the measurement on the surface of the Earth and provides insight into the fidelity of the geolocation determination process. Surfaces well characterized by independent methods are well suited to provide a measure of the ICESat-2 geolocation accuracy through statistical comparison. This study compares airborne lidar data with the ICESat-2 along-track geolocated photon data product to determine the horizontal geolocation accuracy by minimizing the vertical residuals between datasets. At the same location arrays of corner cube retro-reflectors (CCRs) provide unique signal signatures back to the satellite from their known positions to give a deterministic solution of the laser footprint diameter and the geolocation accuracy for those cases where two or more CCRs were illuminated within one ICESat-2 transect. This passive method for diameter recovery and geolocation accuracy assessment is implemented at two locations: White Sands Missile Range (WSMR) in New Mexico and along the 88\u00b0S latitude line in Antarctica. This early on-orbit study provides results as a proof of concept for this passive validation technique. For the cases studied the diameter value ranged from 10.6 to 12 m. The variability is attributed to the statistical nature of photon-counting lidar technology and potentially, variations in the atmospheric conditions that impact signal transmission. The geolocation accuracy results from the CCR technique and airborne lidar comparisons are within the mission requirement of 6.5 m.<\/jats:p>","DOI":"10.3390\/rs12213653","type":"journal-article","created":{"date-parts":[[2020,11,8]],"date-time":"2020-11-08T19:03:37Z","timestamp":1604862217000},"page":"3653","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":135,"title":["Early ICESat-2 on-orbit Geolocation Validation Using Ground-Based Corner Cube Retro-Reflectors"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7564-1193","authenticated-orcid":false,"given":"Lori","family":"Magruder","sequence":"first","affiliation":[{"name":"Applied Research Laboratories, University of Texas at Austin, Austin, TX 78712, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6462-6112","authenticated-orcid":false,"given":"Kelly","family":"Brunt","sequence":"additional","affiliation":[{"name":"National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, MD 20771, USA"},{"name":"University of Maryland, College Park, MD 20742, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Alonzo","sequence":"additional","affiliation":[{"name":"Applied Research Laboratories, University of Texas at Austin, Austin, TX 78712, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"735","DOI":"10.1109\/JPROC.2009.2034765","article-title":"The ICESat-2 laser altimetry mission","volume":"98","author":"Abdalati","year":"2010","journal-title":"Proc. IEEE"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.rse.2016.12.029","article-title":"The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2): Science requirements, concept, and implementation","volume":"190","author":"Markus","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1239","DOI":"10.1126\/science.aaz5845","article-title":"Pervasive ice sheet mass loss driven by competing ocean and atmosphere processes","volume":"368","author":"Smith","year":"2020","journal-title":"Science"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"C08010","DOI":"10.1029\/2008JC004753","article-title":"ICESat over Arctic sea ice: Estimation of snow depth and ice thickness","volume":"113","author":"Kwok","year":"2008","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41467-018-04173-0","article-title":"Quantifying climate feedbacks in polar regions","volume":"9","author":"Goosse","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"eaav4236","DOI":"10.1126\/science.aav4236","article-title":"Pantropical climate interactions","volume":"363","author":"Cai","year":"2019","journal-title":"Science"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Yang, G., Martino, A.J., Lu, W., Cavanaugh, J., Bock, M., and Krainak, M.A. (2019). ICESat-2 ATLAS photon-counting receiver: Initial on-orbit performance. Proc. SPIE Def. Commer. Sens., 10978.","DOI":"10.1117\/12.2520626"},{"key":"ref_8","unstructured":"Martino, A., Bock, M.R., Jones, R.L., Neumann, T.A., Hancock, D.W., Dabney, P.W., and Webb, C.E. (2020, November 01). The Ice, Cloud and Land Elevation Satellite-2 Project: Algorithm Theoretical Basis Document (ATBD) for ATL02 (Level 1B) Data Product, NASA Tech. Document, ICESat-2-SIPS-SPEC-0150, Available online: https:\/\/ICESat-2.gsfc.nasa.gov\/sites\/default\/files\/page_files\/ICESat2_ATL02_ATBD_r003.pdf."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"111325","DOI":"10.1016\/j.rse.2019.111325","article-title":"The Ice, Cloud and land Elevation Satellite-2: A global geolocated photon product derived from the Advanced Topographic Laser Altimeter System","volume":"233","author":"Neumann","year":"2019","journal-title":"Remote Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"L21S04","DOI":"10.1029\/2005GL023504","article-title":"In Situ Timing and Pointing Verification of the ICESat Altimeter using a Ground Based System","volume":"32","author":"Magruder","year":"2005","journal-title":"Geophys. Res. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1109\/TGRS.2006.885070","article-title":"ICESat elevation Data Product Verification at White Sands Space Harbor","volume":"45","author":"Magruder","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2911","DOI":"10.1109\/TGRS.2017.2786659","article-title":"Performance analysis of airborne photon-counting lidar data in preparation for the ICESat-2 mission","volume":"56","author":"Magruder","year":"2018","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1029\/GD025p0133","article-title":"Millimeter Accuracy Satellite Laser Ranging: A Review","volume":"Volume 25","author":"Degnan","year":"1993","journal-title":"Contributions of Space Geodesy to Geodynamics: Technology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"9259","DOI":"10.1364\/AO.58.009259","article-title":"Small and lightweight laser retro-reflector arrays for lunar landers","volume":"58","author":"Sun","year":"2019","journal-title":"Appl. Opt."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Luthcke, S.B., Carabajal, C.C., and Rowlands, D.D. (2002). Enhanced geolocation of spaceborne laser altimeter surface returns: Parameter calibration from the simultaneous reduction of altimeter range and navigation tracking data. J. Geodyn., 34.","DOI":"10.1016\/S0264-3707(02)00047-9"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1364\/JOSA.61.000431","article-title":"The far field diffraction pattern for corner reflectors with complex reflection coefficients","volume":"61","author":"Chang","year":"1971","journal-title":"J. Opt. Soc. Am."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Martino, A., Neumann, T.A., Kurtz, N.T., and McLennan, D. (2019, January 9\u201312). ICESat-2 mission overview and early performance. Proceedings of the SPIE 11151, Sensors, Systems and Next-Generation Satellites XXIII, Strasbourg, France.","DOI":"10.1117\/12.2534938"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"L21S07","DOI":"10.1029\/2005GL023800","article-title":"ICESat range and mounting bias estimation over precisely-surveyed terrain","volume":"32","author":"Martin","year":"2005","journal-title":"Geophys. Res. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"L21S05","DOI":"10.1029\/2005GL023689","article-title":"Reduction of ICESat systematic geolocation errors and he impact on ice sheet elevation change detection","volume":"32","author":"Luthcke","year":"2005","journal-title":"Geophys. Res. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"L22S11","DOI":"10.1029\/2005GL024005","article-title":"The transmitter pointing determination in the Geoscience Laser Altimeter System","volume":"32","author":"Sirota","year":"2005","journal-title":"Geophys. Res. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"13072","DOI":"10.1029\/2019GL084886","article-title":"Assessment of ICESat-2 Ice Sheet Surface Heights, Based on Comparisons over the Interior of the Antarctic Ice Sheet","volume":"46","author":"Brunt","year":"2019","journal-title":"Geophys. Res. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"570","DOI":"10.5194\/tc-13-579-2019","article-title":"Assessment of altimetry using ground-based GPS data from the 88S Traverse, Antarctica, in support of ICESat-2","volume":"13","author":"Brunt","year":"2019","journal-title":"Cryosphere"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"467","DOI":"10.3189\/S002214300001844X","article-title":"On the accumulation and seasonal stratification of snow at the South Pole","volume":"5","author":"Gow","year":"1965","journal-title":"J. Glaciol."},{"key":"ref_24","unstructured":"Bae, S., Helgeson, B., James, M., and Sipps, J. (2019). ICESat-2 Precision Pointing Determination, American Astronautical Society. AAS Paper 19-777."},{"key":"ref_25","unstructured":"Luthcke, S. Personal communication."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/21\/3653\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:30:36Z","timestamp":1760178636000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/21\/3653"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,11,7]]},"references-count":25,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2020,11]]}},"alternative-id":["rs12213653"],"URL":"https:\/\/doi.org\/10.3390\/rs12213653","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,11,7]]}}}