{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,8]],"date-time":"2026-02-08T04:10:52Z","timestamp":1770523852844,"version":"3.49.0"},"reference-count":16,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2023,6,30]],"date-time":"2023-06-30T00:00:00Z","timestamp":1688083200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"U.S. Geological Survey","award":["G19AC00176"],"award-info":[{"award-number":["G19AC00176"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>With the launch of Landsat-9 on 27 September 2021, Landsat continues its fifty-year continuity mission of providing users with calibrated Earth observations. It has become a requirement that an underflight experiment be performed during commissioning to support sensor cross-calibration. In this most recent experiment, Landsat-9 flew under Landsat-8 for nearly three days with over 50% ground overlap, from 13 to 15 November 2021. To address the scarcity of reference data that are available to support calibration and validation early-on in the mission, a ground campaign was planned and executed by the Rochester Institute of Technology (RIT) on 14 November 2021 to provide full spectrum measurements for early mission comparisons. The primary experiment was conducted in the Outer Banks, North Carolina at Jockey\u2019s Ridge Sand Dunes. Full-spectrum ground-based measurements were acquired with calibrated reference equipment, while a novel Unmanned Aircraft System (UAS)-based platforms acquired hyperspectral visible and near-infrared (VNIR)\/Short-wave infrared (SWIR) imagery data and coincident broadband cooled thermal infrared (TIR) imagery. Results of satellite\/UAS\/ground comparisons were an indicator, during the commissioning phase, that Landsat-9 is behaving consistently with Landsat-8, ground reference, and UAS measurements. In the thermal infrared, all measurements agree to be within 1 K over water and to within 2 K over sand, which represents the most challenging material for estimating surface temperature. For the surface reflectance product(s), Landsat-8 and -9 are in good agreement and only deviate slightly from ground reference in the SWIR bands; a deviation of 2% in the VNIR and 5\u20138% in the SWIR regime. Subsequent longer-term studies indicate that Landsat 9 continues to perform as expected. The behavior of Thermal Infrared Sensor-2 (TIRS-2) against reference is also shown for the first year of the mission to illustrate its consistent performance.<\/jats:p>","DOI":"10.3390\/rs15133370","type":"journal-article","created":{"date-parts":[[2023,7,3]],"date-time":"2023-07-03T00:49:27Z","timestamp":1688345367000},"page":"3370","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Validation of Landsat-9 and Landsat-8 Surface Temperature and Reflectance during the Underfly Event"],"prefix":"10.3390","volume":"15","author":[{"given":"Rehman","family":"Eon","sequence":"first","affiliation":[{"name":"Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA"}]},{"given":"Aaron","family":"Gerace","sequence":"additional","affiliation":[{"name":"Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA"}]},{"given":"Lucy","family":"Falcon","sequence":"additional","affiliation":[{"name":"Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA"}]},{"given":"Ethan","family":"Poole","sequence":"additional","affiliation":[{"name":"Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4691-5129","authenticated-orcid":false,"given":"Tania","family":"Kleynhans","sequence":"additional","affiliation":[{"name":"Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA"}]},{"given":"Nina","family":"Raque\u00f1o","sequence":"additional","affiliation":[{"name":"Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA"}]},{"given":"Timothy","family":"Bauch","sequence":"additional","affiliation":[{"name":"Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623, USA"}]}],"member":"1968","published-online":{"date-parts":[[2023,6,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kaita, E., Markham, B., Haque, M.O., Dichmann, D., Gerace, A., Leigh, L., Good, S., Schmidt, M., and Crawford, C.J. (2022). Landsat 9 Cross Calibration Under-Fly of Landsat 8: Planning, and Execution. Remote Sens., 14.","DOI":"10.3390\/rs14215414"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"113086","DOI":"10.1016\/j.rse.2022.113086","article-title":"In-flight performance of the Multi-band Uncooled Radiometer Instrument (MURI) thermal sensor","volume":"279","author":"Gerace","year":"2022","journal-title":"Remote Sens. Environ."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3270","DOI":"10.1038\/s41598-021-82783-3","article-title":"Mapping barrier island soil moisture using a radiative transfer model of hyperspectral imagery from an unmanned aerial system","volume":"11","author":"Eon","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Kaputa, D.S., Bauch, T., Roberts, C., McKeown, D., Foote, M., and Salvaggio, C. (2019, January 25\u201327). Mx-1: A new multi-modal remote sensing UAS payload with high accuracy GPS and IMU. 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Historic Thermal Calibration of Landsat 5 TM through an Improved Physics Based Approach, Rochester Institute of Technology."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Gross, G., Helder, D., Begeman, C., Leigh, L., Kaewmanee, M., and Shah, R. (2022). Initial Cross-Calibration of Landsat 8 and Landsat 9 Using the Simultaneous Underfly Event. Remote Sens., 14.","DOI":"10.3390\/rs14102418"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/13\/3370\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:04:24Z","timestamp":1760126664000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/13\/3370"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,6,30]]},"references-count":16,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2023,7]]}},"alternative-id":["rs15133370"],"URL":"https:\/\/doi.org\/10.3390\/rs15133370","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,6,30]]}}}