{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,19]],"date-time":"2026-05-19T23:09:43Z","timestamp":1779232183207,"version":"3.51.4"},"reference-count":42,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,5,25]],"date-time":"2021-05-25T00:00:00Z","timestamp":1621900800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000203","name":"U.S. Geological Survey","doi-asserted-by":"publisher","award":["G19AS00001"],"award-info":[{"award-number":["G19AS00001"]}],"id":[{"id":"10.13039\/100000203","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The remote sensing community has extensively used Pseudo-Invariant Calibration Sites (PICS) to monitor the long-term in-flight radiometric calibration of Earth-observing satellites. The use of the PICS has an underlying assumption that these sites are invariant over time. However, the site\u2019s temporal stability has not been assured in the past. This work evaluates the temporal stability of PICS by not only detecting the trend but also locating significant shifts (change points) lying behind the time series. A single time series was formed using the virtual constellation approach in which multiple sensors data were combined for each site to achieve denser temporal coverage and overcome the limitation of dependence related to a specific sensor. The sensors used for this work were selected based on radiometric calibration uncertainty and availability of the data: operational land imager (Landsat-8), enhanced thematic mapper (Landsat-7), moderate resolution imaging spectroradiometer (Terra and Aqua), and multispectral instrument (Sentinel-2A). An inverse variance weighting method was applied to the Top-of-Atmosphere (TOA) reflectance time series to reveal the underlying trend. The sequential Mann\u2013Kendall test was employed upon the weighted TOA reflectance time-series recorded over 20 years to detect abrupt changes for six reflective bands. Statistically significant trends and abrupt changes have been detected for all sites, but the magnitude of the trends (maximum of 0.215% change in TOA reflectance per year) suggest that these sites are not changing substantially over time. Hence, it can be stated that despite minor changes in all evaluated PICS, they can be used for radiometric calibration of optical remote sensing sensors. The new approach provides useful results by revealing underlying trends and providing a better understanding of PICS\u2019 stability.<\/jats:p>","DOI":"10.3390\/rs13112079","type":"journal-article","created":{"date-parts":[[2021,5,25]],"date-time":"2021-05-25T22:02:23Z","timestamp":1621980143000},"page":"2079","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Detection of Change Points in Pseudo-Invariant Calibration Sites Time Series Using Multi-Sensor Satellite Imagery"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1040-1804","authenticated-orcid":false,"given":"Neha","family":"Khadka","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering and Computer Science, South Dakota State University, Brookings, SD 57007, USA"},{"name":"Imaging Center, Image Processing Laboratory, South Dakota State University (SDSU), Brookings, SD 57007, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2895-8697","authenticated-orcid":false,"given":"Cibele","family":"Teixeira Pinto","sequence":"additional","affiliation":[{"name":"Imaging Center, Image Processing Laboratory, South Dakota State University (SDSU), Brookings, SD 57007, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0836-4768","authenticated-orcid":false,"given":"Larry","family":"Leigh","sequence":"additional","affiliation":[{"name":"Imaging Center, Image Processing Laboratory, South Dakota State University (SDSU), Brookings, SD 57007, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"199","DOI":"10.6028\/jres.108.020","article-title":"Radiometric measurement comparison on the integrating sphere source used to calibrate the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Landsat 7 Enhanced Thematic Mapper Plus (ETM+)","volume":"108","author":"Butler","year":"2003","journal-title":"J. Res. Natl. Inst. Stand. Technol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"5879","DOI":"10.1364\/AO.41.005879","article-title":"Realization of the National Institute of Standards and Technology detector-based spectral irradiance scale","volume":"41","author":"Yoon","year":"2002","journal-title":"Appl. Optics"},{"key":"ref_3","unstructured":"USGS (2021, January 03). Landsat Missions, Available online: https:\/\/www.usgs.gov\/core-science-systems\/nli\/landsat\/landsat-collection-1-level-1-quality-assessment-band?qt-science_support_page_related_con=0#qt-science_support_page_related_con."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Morstad, D.L., and Helder, D.L. (2008, January 22\u201327). Use of pseudo-invariant sites for long-term sensor calibration. Proceedings of the IGARSS 2008-2008 IEEE International Geoscience and Remote Sensing Symposium, Boston, MA, USA.","DOI":"10.1109\/IGARSS.2008.4778841"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1109\/TGRS.2003.815406","article-title":"Evaluation of radiative transfer simulations over bright desert calibration sites","volume":"42","author":"Govaerts","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"12619","DOI":"10.3390\/rs61212619","article-title":"Radiometric cross calibration of Landsat 8 operational land imager (OLI) and Landsat 7 enhanced thematic mapper plus (ETM+)","volume":"6","author":"Mishra","year":"2014","journal-title":"Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"873","DOI":"10.1080\/2150704X.2013.809496","article-title":"Impact of Terra MODIS Collection 6 on long-term trending comparisons with Landsat 7 ETM+ reflective solar bands","volume":"4","author":"Angal","year":"2013","journal-title":"Remote Sens. Lett."},{"key":"ref_8","unstructured":"Vuppula, H. (2017). Normalization of pseudo-invariant calibration sites for increasing the temporal resolution and long-term trending. [Master\u2019s Thesis, South Dakota State University]."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"386","DOI":"10.1109\/JSTARS.2013.2251999","article-title":"Radiometric cross-calibration of EO-1 ALI with L7 ETM+ and Terra MODIS sensors using near-simultaneous desert observations","volume":"6","author":"Chander","year":"2013","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"147","DOI":"10.4236\/ars.2017.62011","article-title":"Sentinel-2 MSI radiometric characterization and cross-calibration with Landsat-8 OLI","volume":"6","author":"Li","year":"2017","journal-title":"Adv. Remote Sens."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1360","DOI":"10.1109\/TGRS.2013.2243738","article-title":"Absolute radiometric calibration of Landsat using a pseudo invariant calibration site","volume":"51","author":"Helder","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Raut, B., Kaewmanee, M., Angal, A., Xiong, X., and Helder, D. (2019). Empirical Absolute Calibration Model for Multiple Pseudo-Invariant Calibration Sites. Remote Sens., 11.","DOI":"10.3390\/rs11091105"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Tuli, F.T.Z., Pinto, C.T., Angal, A., Xiong, X., and Helder, D. (2019). New Approach for Temporal Stability Evaluation of Pseudo-Invariant Calibration Sites (PICS). Remote Sens., 11.","DOI":"10.3390\/rs11121502"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.rse.2018.09.002","article-title":"The Harmonized Landsat and Sentinel-2 surface reflectance data set","volume":"219","author":"Claverie","year":"2018","journal-title":"Remote Sens. Environ."},{"key":"ref_15","unstructured":"CEOS (2020, October 15). Virtual Constellations. Available online: http:\/\/ceos.org\/ourwork\/virtual-constellations\/."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.rse.2015.09.001","article-title":"Virtual constellations for global terrestrial monitoring","volume":"170","author":"Wulder","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_17","unstructured":"USGS (2020, October 15). Landsat Missions, Available online: https:\/\/www.usgs.gov\/core-science-systems\/nli\/landsat."},{"key":"ref_18","unstructured":"Barsi, J.A., Markham, B.L., Czapla-Myers, J.S., Helder, D.L., Hook, S.J., Schott, J.R., and Haque, M.O. (September, January 30). Landsat-7 ETM+ radiometric calibration status. Proceedings of the Earth Observing Systems XXI, San Diego, CA, USA."},{"key":"ref_19","unstructured":"ESA (2020, October 17). Mission Objectives. Available online: https:\/\/sentinels.copernicus.eu\/web\/sentinel\/missions\/sentinel-2\/mission-objectives."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Gascon, F., Bouzinac, C., Th\u00e9paut, O., Jung, M., Francesconi, B., Louis, J., Lonjou, V., Lafrance, B., Massera, S., and Gaudel-Vacaresse, A. (2017). Copernicus Sentinel-2A calibration and products validation status. Remote Sens., 9.","DOI":"10.3390\/rs9060584"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"822","DOI":"10.1080\/22797254.2018.1507613","article-title":"Sentinel-2A MSI and Landsat-8 OLI radiometric cross comparison over desert sites","volume":"51","author":"Barsi","year":"2018","journal-title":"Eur. J. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Barnes, W.L., and Salomonson, V.V. (1992, January 16). MODIS: A global imaging spectroradiometer for the Earth Observing System. Proceedings of the Optical Technologies for Aerospace Sensing: A Critical Review, Boston, MA, USA.","DOI":"10.1117\/12.161578"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"879","DOI":"10.1109\/TGRS.2006.890567","article-title":"Multiyear on-orbit calibration and performance of Terra MODIS reflective solar bands","volume":"45","author":"Xiong","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1109\/TGRS.2009.2024307","article-title":"On-orbit calibration and performance of Aqua MODIS reflective solar bands","volume":"48","author":"Xiong","year":"2009","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1327","DOI":"10.3390\/rs6021327","article-title":"Absolute calibration of optical satellite sensors using Libya 4 pseudo invariant calibration site","volume":"6","author":"Mishra","year":"2014","journal-title":"Remote Sens."},{"key":"ref_26","unstructured":"Goddard Space Flight Center, and Landsat 7 Project Science Office (1999). Landsat 7: Science Data User\u2019s Handbook."},{"key":"ref_27","unstructured":"USGS (2019). Landsat 8 Data Users Handbook."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5267","DOI":"10.1080\/01431160412331269779","article-title":"A new method for cross-calibration of two satellite sensors","volume":"25","author":"Liu","year":"2004","journal-title":"Int. J. Remote Sens."},{"key":"ref_29","first-page":"1855","article-title":"Operational BRDF effects correction for wide-field-of-view optical scanners (BREFCOR)","volume":"53","author":"Richter","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Farhad, M., Kaewmanee, M., Leigh, L., and Helder, D. (2020). Radiometric Cross Calibration and Validation Using 4 Angle BRDF Model between Landsat 8 and Sentinel 2A. Remote Sens., 12.","DOI":"10.3390\/rs12050806"},{"key":"ref_31","unstructured":"Kaewmanee, M. (2018, January 18\u201320). Pseudo invariant calibration sites: PICS evolution. Proceedings of the CALCON 2018, Utah State University, Logan, UT, USA."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Tucker, J., and Ortiz, M. (2007). Weighting Individual Datum for Nonparametric Analysis. Proc. Am. Soc. Min. Reclam., 831\u2013836.","DOI":"10.21000\/JASMR07010831"},{"key":"ref_33","unstructured":"Bevington, P.R., and Robinson, D.K. (2003). Data Reduction and Error Analysis, McGraw Hill."},{"key":"ref_34","unstructured":"Sneyers, R. (1991). On the Statistical Analysis of Series of Observations, Secretariat of the World Meteorological Organization."},{"key":"ref_35","first-page":"5319","article-title":"Application of sequential Mann-Kendall test for detection of approximate significant change point in surface air temperature for Kolkata weather observatory, west Bengal, India","volume":"6","author":"Bisai","year":"2014","journal-title":"Int. J. Curr. Res."},{"key":"ref_36","first-page":"90","article-title":"Meteorological trend analysis in Western Rajasthan (India) using geographical information system and statistical techniques","volume":"5","author":"Kundu","year":"2015","journal-title":"J. Environ. Earth Sci."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Chatterjee, S., Bisai, D., and Khan, A. (2014). Detection of Approximate Potential Trend Turning Points in Temperature Time Series (1941-2010) for Asansol Weather Observation Station, West Bengal, India. Atmos. Clim. Sci., 4.","DOI":"10.4236\/acs.2014.41009"},{"key":"ref_38","unstructured":"Kendall, M.G. (1948). Rank Correlation Methods, Hafner Publishing Company."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Mann, H.B. (1945). Nonparametric tests against trend. Econom. J. Econom. Soc., 245\u2013259.","DOI":"10.2307\/1907187"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Militino, A.F., Moradi, M., and Ugarte, M.D. (2020). On the Performances of Trend and Change-Point Detection Methods for Remote Sensing Data. Remote Sens., 12.","DOI":"10.3390\/rs12061008"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1109\/LGRS.2006.869966","article-title":"A new method for retrieving band 6 of Aqua MODIS","volume":"3","author":"Wang","year":"2006","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1016\/j.isprsjprs.2017.07.002","article-title":"Radiometric inter-sensor cross-calibration uncertainty using a traceable high accuracy reference hyperspectral imager","volume":"130","author":"Banks","year":"2017","journal-title":"ISPRS J. Photogramm. Remote Sens."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/11\/2079\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:07:40Z","timestamp":1760162860000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/11\/2079"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,25]]},"references-count":42,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2021,6]]}},"alternative-id":["rs13112079"],"URL":"https:\/\/doi.org\/10.3390\/rs13112079","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,25]]}}}