Poster Session 4, Thursday, October 6, 11:00–12:40
Investigation of Formosat-5 derived suspended sediment concentration over inland and coastal waters
Formosat-5 (FS5) is a Taiwanese satellite that was launched on 25 August 2017. FS5 offers high-resolution (4 m) multispectral images and a one-day revisit time. The present study evaluates the capability of FS5 for mapping suspended sediment concentration (SSC) in inland and coastal waters. We address two main aspects of SSC retrieval from FS5 imagery: (1) removal of atmospheric influence and (2) choice of the SSC retrieval algorithm suitable for rivers and coastal waters in Vietnam and Taiwan. We applied the Dark Spectrum Fitting (DSF) atmospheric correction algorithm after adapting ACOLITE for FS5 image processing. The remote sensing reflectance (Rrs) derived from FS5 images was cross-checked with reference data by using Landsat 8 Operational Land Imager (OLI) images level-2 for two groups of ground targets (bright and dark). As a result, there was a good linear relationship between FS5’s Rrs and OLI’s Rrs. The suspended sediment concentration was derived using a generic single band algorithm integrated with ACOLITE. SSC in the Bacdang River in the north of Vietnam and in a coastal water region in the north of Taiwan was retrieved. Due to the lack of match-up situ measurement data with satellite images, the FS5-derived SSC image was cross-checked with an OLI-derived SSC reference image based on the root mean square error (RMSE) and histogram. The results indicate that FS5-derived SSC gives comparable results to those of OLI over inland and coastal waters.
Chi-Kuei Wang, National Cheng Kung University, [email protected], 0000-0002-9058-3902
Quinten Vanhellemont, Royal Belgian Institute of Natural Sciences, [email protected]