{"id":212,"date":"2016-07-03T10:40:04","date_gmt":"2016-07-03T17:40:04","guid":{"rendered":"https:\/\/live-optics-wp.pantheonsite.io\/rsg\/?page_id=212"},"modified":"2025-09-22T10:43:08","modified_gmt":"2025-09-22T17:43:08","slug":"radcats","status":"publish","type":"page","link":"https:\/\/wp.optics.arizona.edu\/rsg\/resources\/radcats\/","title":{"rendered":"RadCaTS"},"content":{"rendered":"<p>The <strong>Radiometric Calibration Test Site (RadCaTS)<\/strong> facility is a suite of instruments that are used to make in situ measurements of the surface and atmosphere to predict the top-of-atmosphere (TOA) spectral radiance reflected from the Earth\u2019s surface at any time during clear-sky conditions. It is an extension of the measurements made by ground-based personnel using the reflectance-based approach for vicarious calibration, and it is currently in use to validate the radiometric calibration and surface reflectance products of such sensors as <a href=\"http:\/\/landsat.usgs.gov\/landsat8.php\">Landsat 8 OLI<\/a>, <a href=\"http:\/\/landsat.usgs.gov\/about_landsat7.php\">Landsat 7 ETM+<\/a>, <a href=\"http:\/\/modis.gsfc.nasa.gov\/\">Terra and Aqua MODIS<\/a>, <a href=\"http:\/\/www-misr.jpl.nasa.gov\/\">MISR<\/a>, <a href=\"http:\/\/asterweb.jpl.nasa.gov\/\">ASTER<\/a>, <a href=\"http:\/\/www.digitalglobe.com\/about\/our-constellation\">WorldView<\/a>, <a href=\"https:\/\/www.planet.com\/products\/satellite-imagery\/rapid-eye-analytic-ortho-tile\/\">RapidEye<\/a>, and more recently <a href=\"http:\/\/ncc.nesdis.noaa.gov\/VIIRS\/\">SNPP VIIRS<\/a>.<\/p>\n<div style=\"width: 860px;\" class=\"wp-video\"><video class=\"wp-video-shortcode\" id=\"video-212-1\" width=\"860\" height=\"484\" poster=\"https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2023\/06\/Screenshot-2023-06-06-134035.jpg\" preload=\"metadata\" controls=\"controls\"><source type=\"video\/mp4\" src=\"https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2023\/06\/University-of-Arizona-RadCaTS.mp4?_=1\" \/><a href=\"https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2023\/06\/University-of-Arizona-RadCaTS.mp4\">https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2023\/06\/University-of-Arizona-RadCaTS.mp4<\/a><\/video><\/div>\n<p>The RadCaTS surface reflectance measurements are made using multispectral GVRs that were designed, developed, and tested at RSG. The instruments have gone through various upgrades throughout the past decade, and the current design has eight spectral channels. Seven of the eight channels have Silicon detectors, and the eighth channel has an InGaAs detector. Interference filters are used to control the spectral characteristics of each channel.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-220\" title=\"RadCaTS ground-viewing radiometer (GVR) cutaway view\" src=\"http:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/GVR_cutaway-300x207.jpg\" alt=\"RadCaTS ground-viewing radiometer (GVR) cutaway view\" width=\"390\" height=\"269\" srcset=\"https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/GVR_cutaway-300x207.jpg 300w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/GVR_cutaway-768x529.jpg 768w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/GVR_cutaway.jpg 772w\" sizes=\"auto, (max-width: 390px) 100vw, 390px\" \/><img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-171\" title=\"RadCaTS ground-viewing radiometer (GVR) at Railroad Valley\" src=\"http:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/05\/DSC_0096-300x199.jpg\" alt=\"RadCaTS ground-viewing radiometer (GVR) at Railroad Valley\" width=\"399\" height=\"265\" srcset=\"https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/05\/DSC_0096-300x199.jpg 300w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/05\/DSC_0096-768x510.jpg 768w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/05\/DSC_0096-1024x680.jpg 1024w\" sizes=\"auto, (max-width: 399px) 100vw, 399px\" \/><br \/>\n&nbsp;<br \/>\nAtmospheric measurements are made using a <a href=\"http:\/\/www.cimel.fr\/?family=instruments-2&amp;lang=en\">Cimel 318A<\/a> sun photometer that is part of the <a href=\"http:\/\/aeronet.gsfc.nasa.gov\/\">Aerosol Robotic Network (AERONET)<\/a>. RSG currently operates Cimel serial numbers 786 and 314. One is typically in operation at Railroad Valley while the other is being calibrated at NASA Goddard Space Flight Center (GSFC). Measurements of direct sun and sky are made throughout the day in a predetermined sequence, and the data are uploaded to GSFC via a Geostationary Operational Environmental Satellite (GOES West) every hour. The data are processed at GSFC and are downloaded by RSG for use in the RadCaTS processing code.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-221\" title=\"AERONET Cimel sun photometer at Railroad Valley \" src=\"http:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/DSC01064_auto_corrected-300x225.jpg\" alt=\"AERONET Cimel sun photometer at Railroad Valley \" width=\"390\" height=\"293\" srcset=\"https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/DSC01064_auto_corrected-300x225.jpg 300w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/DSC01064_auto_corrected-768x576.jpg 768w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/DSC01064_auto_corrected-1024x768.jpg 1024w\" sizes=\"auto, (max-width: 390px) 100vw, 390px\" \/>\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-222\" title=\"AERONET Cimel sun photometer at Railroad Valley \" src=\"http:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/DSC01067_auto-300x225.jpg\" alt=\"AERONET Cimel sun photometer at Railroad Valley \" width=\"390\" height=\"293\" srcset=\"https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/DSC01067_auto-300x225.jpg 300w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/DSC01067_auto-768x576.jpg 768w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/DSC01067_auto-1024x768.jpg 1024w\" sizes=\"auto, (max-width: 390px) 100vw, 390px\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-263 aligncenter\" src=\"http:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/RadCaTS_transparent_large_logo_final-300x296.png\" alt=\"RadCaTS_transparent_large_logo_final\" width=\"339\" height=\"334\" srcset=\"https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/RadCaTS_transparent_large_logo_final-300x296.png 300w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/RadCaTS_transparent_large_logo_final-768x758.png 768w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/RadCaTS_transparent_large_logo_final-1024x1011.png 1024w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/RadCaTS_transparent_large_logo_final-90x90.png 90w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/RadCaTS_transparent_large_logo_final-75x75.png 75w, https:\/\/wp.optics.arizona.edu\/rsg\/wp-content\/uploads\/sites\/44\/2016\/07\/RadCaTS_transparent_large_logo_final.png 1872w\" sizes=\"auto, (max-width: 339px) 100vw, 339px\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Radiometric Calibration Test Site (RadCaTS) facility is a suite of instruments that are used to make in situ measurements of the surface and atmosphere to predict the top-of-atmosphere (TOA) spectral radiance reflected from the Earth\u2019s surface at any time during clear-sky conditions. It is an extension of the measurements made by ground-based personnel using the reflectance-based approach for vicarious<\/p>\n","protected":false},"author":55,"featured_media":0,"parent":100,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-212","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/pages\/212","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/users\/55"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/comments?post=212"}],"version-history":[{"count":29,"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/pages\/212\/revisions"}],"predecessor-version":[{"id":386,"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/pages\/212\/revisions\/386"}],"up":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/pages\/100"}],"wp:attachment":[{"href":"https:\/\/wp.optics.arizona.edu\/rsg\/wp-json\/wp\/v2\/media?parent=212"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}