Applicability of combined microwave and optical data for surface water quality retrievals

Abstract

This paper presents the applicability of combined microwave (ERS-2 SAR) and optical (Landsat TM) data for surface water quality retrievals. Three surface water quality parameters such as turbidity, Secchi disk depth (SDD), and suspended sediment concentration (SSC) in the Gulf of Finland are estimated using multivariate approach. The results indicate that the visible bands of TM data are somewhat correlated to SAR signals, by which SAR can explain 14. 4% of the variability in TM2 observations. Multivariate analyses show that SAR has some contribution to derive those parameters if they are somewhat correlated to the water surface properties. Although it may be possible to develop algorithms for surface water quality retrievals in which SAR is used as supplementary data to optical observations, it still needs to be refined sufficiently to detect differences within the range of these parameters in the area under study.