An example crossover experiment for testing new vicarious calibration techniques for satellite ocean color radiometry

Kenneth J. Voss, Scott Mclean, Marlon Lewis, Carol Johnson, Stephanie Flora, Michael Feinholz, Mark Yarbrough, Charles Trees, Mike Twardowski, Dennis Clark

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


Vicarious calibration of ocean color satellites involves the use of accurate surface measurements of waterleaving radiance to update and improve the system calibration of ocean color satellite sensors. An experiment was performed to compare a free-fall technique with the established Marine Optical Buoy (MOBY) measurement. It was found in the laboratory that the radiance and irradiance instruments compared well within their estimated uncertainties for various spectral sources. The spectrally averaged differences between the National Institute of Standards and Technology (NIST) values for the sources and the instruments were<2.5% for the radiance sensors and<1.5% for the irradiance sensors. In the field, the sensors measuring the above-surface downwelling irradiance performed nearly as well as they had in the laboratory, with an average difference of<2%.While the water-leaving radiance Lw calculated from each instrument agreed in almost all cases within the combined instrument uncertainties (approximately 7%), there was a relative bias between the two instrument classes/techniques that varied spectrally. The spectrally averaged (400-600 nm) difference between the two instrument classes/techniques was 3.1%. However, the spectral variation resulted in the freefall instruments being 0.2% lower at 450 nm and 5.9% higher at 550 nm. Based on the analysis of one matchup, the bias in Lw was similar to that observed for Lu(1 m) with both systems, indicating the difference did not come from propagating Lu(1 m) to Lw.

Original languageEnglish (US)
Pages (from-to)1747-1759
Number of pages13
JournalJournal of Atmospheric and Oceanic Technology
Issue number10
StatePublished - Oct 2010


  • Buoy observations
  • In situ observations
  • Instrumentation/sensors
  • Optical properties
  • Radiances
  • Satellite observations

ASJC Scopus subject areas

  • Ocean Engineering
  • Atmospheric Science


Dive into the research topics of 'An example crossover experiment for testing new vicarious calibration techniques for satellite ocean color radiometry'. Together they form a unique fingerprint.

Cite this