{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,21]],"date-time":"2026-03-21T19:14:52Z","timestamp":1774120492245,"version":"3.50.1"},"reference-count":20,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2024,1,11]],"date-time":"2024-01-11T00:00:00Z","timestamp":1704931200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"NOAA Center for Satellite Applications and Research (STAR) Product Development Readiness &amp; Applications (PDRA) fund"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>A unique End-of-Life (EOL) Deep Space View Test (DSVT) was performed on 27 November 2021 for the Advanced Microwave Sounding Unit-A (AMSU-A) and the Microwave Humidity Sounder (MHS) onboard the first EUMETSAT MetOp-A satellite in the deorbiting process. The purpose of this test is to recalibrate the antenna sidelobe, to derive antenna emission, and to quantify the in-orbit asymmetric scan biases of AMSU-A and MHS to, ultimately, improve Near Real-Time (NRT) products for MetOp-B and -C and the entire Fundamental Climate Data Records (FCDR). In this study, MetOp-A AMSU-A and MHS EOL DSVT data on 27 November 2021 have been analyzed. The deep space scene antenna temperatures were first applied for the antenna pattern correction; then, the antenna reflector channel emissivity values were derived from the corrected temperatures. For the MHS, the observed scan-angle-dependent brightness temperatures (BTs) for all channels were well behaved after the antenna pattern correction, except for channel 1. The derived antenna reflector emissivity values from this test are 0.0016, 0.0036, 0.0036, and 0.0019 for channels 1, 3, 4, and 5, respectively. For AMSU-A, the deep space view counts were not homogeneous during the test period, exhibiting large variations in the along-track and cross-track directions, mainly due to the instrument temperature\u2019s rapid change during the test period. The large relative noise in the deep space view observations negatively impacted the data quality and limits the value of this test. The large relative noise may contribute to the different emissivity values derived from the same frequency for channels 9 to 14. We also found unexpected scan-angle-dependent BT after antenna pattern correction for quasi-vertical (QV) channels 1 and 2 when compared to the emission model. Further investigation using a simulation confirmed that channels 1 and 2 are QV channels, as designed.<\/jats:p>","DOI":"10.3390\/rs16020299","type":"journal-article","created":{"date-parts":[[2024,1,11]],"date-time":"2024-01-11T08:27:07Z","timestamp":1704961627000},"page":"299","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Estimation of AMSU-A and MHS Antenna Emission from MetOp-A End-of-Life Deep Space View Test"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0279-9405","authenticated-orcid":false,"given":"Yong","family":"Chen","sequence":"first","affiliation":[{"name":"NOAA National Environmental Satellite, Data, and Information Service, Center for Satellite Applications and Research, College Park, MD 20740, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3572-6525","authenticated-orcid":false,"given":"Changyong","family":"Cao","sequence":"additional","affiliation":[{"name":"NOAA National Environmental Satellite, Data, and Information Service, Center for Satellite Applications and Research, College Park, MD 20740, USA"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,11]]},"reference":[{"key":"ref_1","unstructured":"Robel, J., and Graumann, A. (2023, October 03). NOAA KLM User\u2019s Guide. Available online: https:\/\/webapp1.dlib.indiana.edu\/virtual_disk_library\/index.cgi\/2790181\/FID1497\/Klm."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"13463","DOI":"10.1002\/2013JD020389","article-title":"Joint Polar Satellite System: The United States next generation civilian polar-orbiting environmental satellite system","volume":"118","author":"Goldberg","year":"2013","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"D19112","DOI":"10.1029\/2012JD018144","article-title":"Introduction to Suomi national polar-orbiting partnership advanced technology microwave sounder for numerical weather prediction and tropical cyclone applications","volume":"117","author":"Weng","year":"2012","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e2022JD037472","DOI":"10.1029\/2022JD037472","article-title":"Mid-tropospheric layer temperature record derived from satellite microwave sounder observations with backward merging approach","volume":"128","author":"Zou","year":"2023","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1109\/TAP.1974.1140809","article-title":"The recovery of polarized apparent temperature distributions of flat scenes from antenna temperature measurements","volume":"22","author":"Claassen","year":"1974","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1109\/TAP.1975.1141020","article-title":"Antenna temperature for a scanning microwave radiometer","volume":"23","author":"Grody","year":"1975","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1007\/BF00117912","article-title":"Antenna pattern correction procedures for the scanning multichannel microwave radiometer (SMMR)","volume":"18","author":"Njoku","year":"1980","journal-title":"Bound.-Layer Meteorol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1109\/36.485118","article-title":"Measurements of the AMSU-B antenna pattern","volume":"34","author":"Hewison","year":"1996","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1109\/36.739131","article-title":"AMSU\u2013A antenna pattern corrections","volume":"37","author":"Mo","year":"1999","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"11187","DOI":"10.1002\/jgrd.50840","article-title":"Calibration of Suomi national polar-orbiting partnership advanced technology microwave sounder","volume":"118","author":"Weng","year":"2013","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"771","DOI":"10.1109\/LGRS.2012.2223193","article-title":"On convertibility from antenna to sensor brightness temperature for ATMS","volume":"10","author":"Weng","year":"2023","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Weng, F., and Yang, H. (2016). Validation of ATMS calibration accuracy using Suomi NPP pitch maneuver observations. Remote Sens., 8.","DOI":"10.3390\/rs8040332"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"4479","DOI":"10.1109\/TGRS.2016.2542526","article-title":"Estimation of ATMS antenna emission from cold space observations","volume":"54","author":"Yang","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_14","unstructured":"Liu, Q., Kim, E., Leslie, V., Berg, W., Bolen, D., and Ibrahim, W. (2023, December 29). NOAA-20 ATMS TDR\/SDR Validated Maturity Status Report, Available online: https:\/\/www.star.nesdis.noaa.gov\/jpss\/documents\/AMM\/N20\/ATMS_TDR_SDR_Validated.pdf."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Weng, F. (2017). Passive Microwave Remote Sensing of the Earth: For Meteorological Applications, Wiley.","DOI":"10.1002\/9783527336289"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"404","DOI":"10.1109\/TGRS.2020.2992270","article-title":"Derivation and validation of sensor brightness temperatures for Advanced Microwave Sounding Unit-A Instruments","volume":"59","author":"Yan","year":"2021","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2477","DOI":"10.1109\/LGRS.2015.2485945","article-title":"Use of Allan Deviation for Characterizing Satellite Microwave Sounder Noise Equivalent Differential Temperature (NEDT)","volume":"12","author":"Tian","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"4927","DOI":"10.5194\/amt-10-4927-2017","article-title":"Noise performance of microwave humidity sounders over their lifetime","volume":"10","author":"Hans","year":"2017","journal-title":"Atmos. Meas. Tech."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"D00A03","DOI":"10.1029\/2007JD009561","article-title":"Validation of the Community Radiative Transfer Model (CRTM) by using CloudSat data","volume":"113","author":"Chen","year":"2008","journal-title":"J. Goephys. Res."},{"key":"ref_20","unstructured":"Weng, F. (2023, December 29). Suomi NPP ATMS SDR Provisional Product Highlights, Available online: https:\/\/www.star.nesdis.noaa.gov\/jpss\/documents\/AMM\/NPP\/ATMS_SDR_Prov.pdf."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/2\/299\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T13:44:46Z","timestamp":1760103886000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/2\/299"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,1,11]]},"references-count":20,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2024,1]]}},"alternative-id":["rs16020299"],"URL":"https:\/\/doi.org\/10.3390\/rs16020299","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,1,11]]}}}