Removal of Surface-Reflected Light for the Measurement of Remote-Sensing Reflectance from an Above-Surface Platform
Abstract
Using hyperspectral measurements made in the field, we show that the effective sea-surface reflectance (defined as the ratio of the surface-reflected radiance at the specular direction corresponding to the downwelling sky radiance from one direction) varies not only for different measurement scans, but also can differ by a factor of 8 between 400 nm and 800 nm for the same scan. This means that the derived water-leaving radiance (or remote-sensing reflectance) can be highly inaccurate if a spectrally constant value is applied (although errors can be reduced by carefully filtering measured raw data). To remove surface-reflected light in field measurements of remote sensing reflectance, a spectral optimization approach was applied, with results compared with those from remote sensing models and from direct measurements. The agreement from different determinations suggests that reasonable results for remote sensing reflectance of clear blue water to turbid brown water are obtainable from above-surface measurements, even under conditions of high waves.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2010
- Accession Number
- ADA534577
Entities
People
- Curtis Mobley
- Robert A. Arnone
- Yu-hwan Ahn
- Zhong P. Lee
Organizations
- United States Naval Research Laboratory