Directional reflectance studies in support of the Radiometric Calibration Test Site (RadCaTS) at Railroad Valley

Jeffrey S. Czapla-Myers, Craig A. Coburn, Kurtis J. Thome, Brian N. Wenny, Nikolaus J. Anderson

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations


The Radiometric Calibration Test Site (RadCaTS) is a suite of commercial and custom instruments used to make measurements of the surface reflectance and atmosphere throughout the day at Railroad Valley, Nevada. It was developed in response to the need for daily radiometric calibration data for the vast array of Earth-observing sensors on orbit, which is continuously increasing as more nations and private companies launch individual environmental satellites as well as large constellations. The current suite of instruments at RadCaTS includes five ground-viewing radiometers (GVRs), four of which view the surface in a nadir-viewing configuration. Many sensors such as those on Landsat-7 and Landsat-8 view Railroad Valley within 3° of nadir, while others such as those on Sentinel-2A and -2B, RapidEye, Aqua, Suomi NPP, and Terra can view Railroad Valley at off-nadir angles. Past efforts have shown that the surface bidirectional reflectance distribution function (BRDF) has minimal impact on vicarious calibration uncertainties for views <10°, but the desire to use larger view angles has prompted the effort to develop a BRDF correction for data from RadCaTS. The current work investigates the application of Railroad Valley BRDF data derived from a BRF camera developed at the University of Arizona in the 1990s (but is no longer in use) to the current RadCaTS surface reflectance measurements. Also investigated are early results from directional reflectance studies using a mobile spectro-goniometer system during a round-robin field campaign in 2018. This work describes the preliminary results, the effects on current measurements, and the approach for future measurements.

Original languageEnglish (US)
Title of host publicationEarth Observing Systems XXIII
EditorsJames J. Butler, Xiaoxiong Xiong, Xingfa Gu
ISBN (Electronic)9781510620995
StatePublished - 2018
EventEarth Observing Systems XXIII 2018 - San Diego, United States
Duration: Aug 21 2018Aug 23 2018

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherEarth Observing Systems XXIII 2018
Country/TerritoryUnited States
CitySan Diego


  • BRDF
  • BRF
  • Goniometer
  • RadCaTS
  • RadCalNet
  • Radiometric calibration
  • Surface reflectance

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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