Self-Shading Corrections for Oceanographic Upwelling Radiometers
Abstract
Most commercially available instruments for measuring upwelling radiance are large enough that they suffer from significant self-shading error over at least some portion of the measured spectrum. The amount of error depends on instrument dimensions, sensor FOV, water optical properties (which are wavelength-dependent), water depth, seafloor optical properties, Sun position, atmospheric conditions. We derive analytical models for the self-shading of a buoyed or nonbuoyed radiometer in optically deep and very shallow waters. The shallow-water and deepwater models are then combined to form a complete analytical model for any water depth. We have modified a previously written Backward Monte Carlo program to numerically compute the self-shading of a buoyed or nonbuoyed radiometer. The results of these numerical simulations can be used to valid the analytical model for a particular instrument or to build a semi-analytical model. We have also written a computer program that applies self-shading corrections to upwelling radiance spectra.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 06, 2004
- Accession Number
- ADA425739
Entities
People
- Curtis D. Mobley
- Curtiss O. Davis
- Robert A. Leathers
- T. V. Downes
Organizations
- United States Naval Research Laboratory