Optical Moorings-of-Opportunity for Validation of Ocean Color Satellites

• Main Authors: Kuwahara, Victor S, Chang, Grace, Zheng, Xiaobing, Dickey, Tommy D, Jiang, Songnian
• Format: Report
• Language: English
• Subjects: ARTIFICIAL SATELLITES; ATMOSPHERIC CORRECTIONS; BTM(BERMUDA TESTBED MOORING); CALIBRATION; DATA PROCESSING; INSTRUMENTATION; Marine Engineering; MEASUREMENT; MOORING BUOYS; OPTICS; Physical and Dynamic Oceanography; REPRINTS; SATELLITE OCEAN COLOR DATA; STANDARDIZATION; TIME SERIES ANALYSIS; Unmanned Spacecraft; VALIDATION; WATER COLUMN; WIND

Buoy-mooring platforms are advantageous for time-series validation and vicarious calibration of ocean color satellites because of their high temporal resolution and ability to perform under adverse weather conditions. Bio-optical data collected on the Bermuda Testbed Mooring (BTM) were used for comparison with satellite ocean color data in an effort to further standardize sampling and data processing methods for high quality satellite-mooring comparisons. Average percentage differences between satellite-measured and mooring-derived water leaving radiances were about 20% at the blue wavelengths, decreasing to as low as 11% in the blue-green to green wavebands. Based on a series of data processing methods and analyses, recommendations concerning rigor of quality control for collected data, optimal averaging of high frequency data, sensor self-shading wind corrections, and instrumentation placement requirements are given for the design and application of optical moorings for ocean color satellite validation. Although buoy-mooring platforms are considered to be among the very best methods to validate ocean color satellite measurements, matchup discrepancies due to water column variability and atmospheric corrections remain important issues. Published in the Journal of Oceanogrpahy v64 p691-703, 2008. Sponsored in part by NSF under Grant Nos. OCE-962781, OCE-09730471 and OCE-9829477 and by NASA under Grant No. NAS5-97127.