EVALUATION OF ATMOSPHERIC CORRECTION AND CHLOROPHYLL ALGORITHMSFOR PROCESSING SEAWIFS DATA

摘要

Producing chlorophyll imagery from SeaWiFS data requires both an atmospheric correction and achlorophyll algorithm. We know of at least 6 atmospheric corrections and 5 chlorophyll algorithms.Even with a valid chlorophyll algorithm, an inappropriate atmospheric correction can lead to invalidresults. Applied scientists and managers may not always use a chlorophyll algorithm that generatesthe best available satellite product for their areas of interest, and would not be able to evaluate thevalidity of the atmospheric correction. The objective of this study is to determine the best overallglobal atmospheric correction and the best overall regional chlorophyll algorithms for differentcoastal regions of the US. We used 159 same-day field-satellite pairs of remote sensing reflectancespectra to determine the best atmospheric correction applicable to the entire US coastline; and 124same-day field-satellite pairs of chlorophyll to determine the most appropriate regional chlorophyllalgorithms. The field measurements were obtained from NOAA coops and NASA SIMBIOSdatabase (Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies).The selection procedure is designed to determine an algorithm that works best over a range of watertypes, and compensates for local variability. Our results indicate a NOAA atmospheric correctionestimated the best overall accurate remote sensing reflectance. Different algorithms apply tochlorophyll: NOAA chlorophyll algorithm for US Gulf of Mexico and Southeast, and central Gulf ofMaine; NASA OC2V2, for California.