TOTAL SUSPENDED MATTER MAPS FROM CHRIS IMAGERY OF A SMALL INLANDWATER BODY IN OOSTENDE (BELGIUM)

摘要

It has been already established that total suspendedrnmatter (TSM) can be retrieved from CHRIS imagery forrnturbid coastal waters, but what about inland waters?rnBecause of the high resolution of CHRIS/PROBArnimages, inland waters not visible by sensors likernSeaWiFS, MERIS and MODIS become detectable andrnare expected to become a key new application domainrnfor optical remote sensing. In the Oostende test siternthere is a small (800m*1400m) inland water body withrnan average depth of 1.5m called the Spuikom. On 6 Julyrn2004, a cloud free CHRIS acquisition of the Oostenderntest site occurred with simultaneous in siturnmeasurements.rnThe reprocessed dataset is evaluated and analyzed. Datarnfrom CHRIS show abnormally high near infrared (NIR)rnreflectance in the lake, especially near the borders. Thisrndoes not significantly affect TSM maps but doesrncontaminate the chlorophyll maps deduced from CHRISrnimagery. This high NIR reflectance is probably causedrnby adjacency effects, although the possibility of bottomrnreflection must also be assessed. In the summer of 2005rna measurement campaign is planned to investigaternfurther the influence of nearby land and bottomrnreflection in order to provide a benchmark dataset forrntesting of algorithms to detect and correct for suchrneffects. CHRIS images will be an important componentrnof this dataset.