Comparison of remote sensing reflectance derived from in-water and above-water radiometric measurements

Abstract

This study provides a qualitative evaluation of R_rs derived from the two hyperspectral above-water radiometers ASD FeildSpec® and TriOS RAMSES®, by comparing them with independent in-water radiometers Satlantic Profiler-II® and skylight-blocked approach (SBA)(Shang et al. 2017 Lee et al. 2013). The R_rs estimation with the in-water radiometers involves less uncertainty than above-radiometers, because it extrapolates in-water upwelling radiance up to the surface for estimating water-leaving radiance without going through the sky glint removal. Coincident field measurements of 4 instruments were obtained in Korea-US joint field campaign for ocean color (KORUS-OC) that were conducted during May, 20th &#8211 June, 6th 2016, around the Korean seas. Among the entire data set, it was found that 41 cases have simultaneous deployment (less than 30 minutes between instruments) of at least one pair of above-water and in-water instrument, allowing qualitative comparison between them.ht-blocked approach (SBA)(Shang et al. 2017 Lee et al. 2013). The R_rs estimation with the in-water radiometers involves less uncertainty than above-radiometers, because it extrapolates in-water upwelling radiance up to the surface for estimating water-leaving radiance without going through the sky glint removal. Coincident field measurements of 4 instruments were obtained in Korea-US joint field campaign for ocean color (KORUS-OC) that were conducted during May, 20th &#8211 June, 6th 2016, around the Korean seas. Among the entire data set, it was found that 41 cases have simultaneous deployment (less than 30 minutes between instruments) of at least one pair of above-water and in-water instrument, allowing qualitative comparison between them.