Spectral Variability of Airborne Ocean Color Data Linked to Variations in Lidar Backscattering Profiles
Abstract
Characterization of 3-D underwater light fields from above the sea surface requires passive and active remote sensing measurements. In this work, we suggest the use of passive ocean color sensors and lidar (Light Detection and Ranging) to examine the vertical structure of optical properties in marine waters of the Northern Part of the Gulf of Alaska (NGOA). We collected simultaneous airborne remote sensing reflectance (Rrs) in the spectral range 443-780 nm (MicroSAS, Satlantic) and lidar-derived volume backscattering (beta) profiles (0-20 m depth, wavelength = 532 nm) during August 17 2002 in shelf waters situated south of Kodiak Island off Alaska (57.48 degrees-58.04 degrees N, 152.91 degrees-151.67 degrees W). We evaluated the spectral response of Rrs to perturbations on the vertical distribution of beta by comparing the spatial variability between aggregated (250 m horizontal resolution x 1 m vertical resolution) Rrs spectral ratios and different lidar statistics per bin (Maximum beta per bin, mean beta per bin, beta(sub m), standard deviation of beta per bin, beta(sub std), integrated beta per bin, beta(sub int) or group of bins (lidar volume extinction coefficient of beta between 0 and 5 m depth). Sub-surface changes of beta(sub m), beta(sub int), and beta(sub std) were mainly correlated with Rrs (490)/Rrs (555) variability along the flight-track (Semi-partial correlation coefficients = 0.12 to 0.21). Our results evidenced linkages between above and below-sea surface optical properties that can be used to derive water optical constituents as a function of depth based on combined passive-active data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2009
- Accession Number
- ADA512871
Entities
People
- Deric J Gray
- J. Churnside
- M. A. Montes-hugo
- Richard W Gould
- Robert A. Arnone
- Zhong-ping Lee
Organizations
- United States Naval Research Laboratory