• Aiken, J., and I. Bellan, 1990: Optical oceanography: An assessment of a towed method. Light and Life in the Sea, P. J. Herring, Ed., Cambridge University Press, 39–57.

  • Hooker, S. B., and W. E. Esaias, 1993: An overview of the SeaWiFS project. Eos, Trans. Amer. Geophys. Union,74, 241–246.

    • Crossref
    • Export Citation
  • ——, C. R. McClain, and A. Holmes, 1993: Ocean color imaging: CZCS to SeaWiFS. Mar. Tech. Soc. J.,27, 3–15.

  • Johnson, B. C., P.-S. Shaw, S. B. Hooker, and D. Lynch, 1998: Radiometric and engineering performance of the SeaWiFS Quality Monitor (SQM): A portable light source for field radiometers. J. Atmos. Oceanic Technol.,15, 1008–1022.

    • Crossref
    • Export Citation
  • McClain, C. R., W. E. Esaias, W. Barnes, B. Guenther, D. Endres, S. B. Hooker, G. Mitchell, and R. Barnes, 1992: Calibration and validation plan for SeaWiFS. NASA Tech. Memo. 104566, Vol. 3, S. B. Hooker and E. R. Firestone, Eds., NASA/Goddard Space Flight Center, Greenbelt, MD. 41 pp. [Available from NASA Center for Aerospace Information, 7121 Standard Drive, Hanover, MD 21076-1320.].

  • Mueller, J. L., and R. W. Austin, 1995: Ocean optics protocols for SeaWiFS validation, revision 1. NASA Tech. Memo. 104566, Vol. 25, S. B. Hooker and E. R. Firestone, Eds., NASA/Goddard Space Flight Center, Greenbelt, MD. 66 pp. [Available from NASA Center for Aerospace Information, 7121 Standard Drive, Hanover, MD 21076-1320.].

  • Robins, D. B., and J. Aiken, 1996: The Atlantic Meridional Transect:An oceanographic research programme to investigate physical, chemical, biological, and optical variables of the Atlantic Ocean. Underwater Tech.,21, 8–14.

    • Crossref
    • Export Citation
  • ——, and Coauthors, 1996: AMT-1 cruise report and preliminary results. NASA Tech. Memo. 104566, Vol. 35, S. B. Hooker and E. R. Firestone, Eds., NASA/Goddard Space Flight Center, Greenbelt, MD. 87 pp. [Available from NASA Center for Aerospace Information, 7121 Standard Drive, Hanover, MD 21076-1320.].

  • Shaw, P.-S., B. C. Johnson, S. B. Hooker, and D. Lynch, 1997: The SeaWiFS Quality Monitor—A portable field calibrator light source. Proc. SPIE,2963, 772–776.

    • Crossref
    • Export Citation
  • Waters, K. J., R. C. Smith, and M. R. Lewis, 1990: Avoiding ship-induced light-field perturbation in the determination of oceanic optical properties. Oceanogr.,3, 18–21.

    • Crossref
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 203 28 0
PDF Downloads 34 17 0

Calibration Evaluation and Radiometric Testing of Field Radiometers with the SeaWiFS Quality Monitor (SQM)

View More View Less
  • 1 NASA/Goddard Space Flight Center, Laboratory for Hydrospheric Processes, Greenbelt, Maryland
  • | 2 Plymouth Marine Laboratory, Plymouth, United Kingdom
Restricted access

Abstract

One of the goals of calibration and validation programs supporting ocean color satellites is to produce water-leaving radiances with an uncertainty of 5% in clear-water regions. This objective requires field instruments with a calibration and measurement capability that is on the order of 1%. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Project, in collaboration with the National Institute of Standards and Technology, has developed a portable illumination source with three temperature-stabilized internal monitors designed to provide a stable light field for checking the optical stability of radiometers used to measure the in situ optical properties of seawater. This device is called the SeaWiFS Quality Monitor (SQM). A recent field evaluation during an extensive research cruise indicates the SQM has the following capabilities: (a) the SQM can be used to track the stability of field radiometers at less than the 1% level in terms of the radiometric response of the instruments—on average 0.30% (±0.15%) for radiance sensors and 0.58% (±0.20%) for irradiance sensors; (b) the SQM light field is sufficiently stable to allow for a sensitive measure and, thus, modeling of changes in the radiometric detectors;(c) based on the radiometers used during the field evaluation, daily SQM measurements are needed to resolve the temporal changes in the response of the sensors; and (d) SQM performance, in terms of the generated light field and the SQM internal monitors, is very stable and decayed only by approximately 0.6% during the course of the 36-day deployment with most of the decay attributed to a change in the operating voltage of one of the lamps.

Corresponding author address: Dr. Stanford B. Hooker, NASA/Goddard Space Flight Center, Greenbelt, MD 20771.

Email: stan@ardbeg.gsfc.nasa.gov

Abstract

One of the goals of calibration and validation programs supporting ocean color satellites is to produce water-leaving radiances with an uncertainty of 5% in clear-water regions. This objective requires field instruments with a calibration and measurement capability that is on the order of 1%. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Project, in collaboration with the National Institute of Standards and Technology, has developed a portable illumination source with three temperature-stabilized internal monitors designed to provide a stable light field for checking the optical stability of radiometers used to measure the in situ optical properties of seawater. This device is called the SeaWiFS Quality Monitor (SQM). A recent field evaluation during an extensive research cruise indicates the SQM has the following capabilities: (a) the SQM can be used to track the stability of field radiometers at less than the 1% level in terms of the radiometric response of the instruments—on average 0.30% (±0.15%) for radiance sensors and 0.58% (±0.20%) for irradiance sensors; (b) the SQM light field is sufficiently stable to allow for a sensitive measure and, thus, modeling of changes in the radiometric detectors;(c) based on the radiometers used during the field evaluation, daily SQM measurements are needed to resolve the temporal changes in the response of the sensors; and (d) SQM performance, in terms of the generated light field and the SQM internal monitors, is very stable and decayed only by approximately 0.6% during the course of the 36-day deployment with most of the decay attributed to a change in the operating voltage of one of the lamps.

Corresponding author address: Dr. Stanford B. Hooker, NASA/Goddard Space Flight Center, Greenbelt, MD 20771.

Email: stan@ardbeg.gsfc.nasa.gov

Save