Monitoring of the Trophic Parameter Chl-a Using Hyperspectral CHRIS-PROBA Data

摘要

The CHRIS sensor, mounted on the PROBA satellite, is one of the first space-borne hyperspectral sensors offering high spatial resolution (18 m x 18 m). This, combined with the possibility of multi-temporal coverage, makes CHRIS-PROBA exceptionally well suited for lake water monitoring. The concept of the project MEMAMON is to monitor the water quality of lakes in the Mecklenburg (Germany) and Mazurian (Poland) lake districts. Both test sites contain a large number of lakes with high variability and different trophic states. This paper presents a study, which aims to determine the trophic parameter chlorophyll-a using hyperspectral CHRIS-PROBA data. To investigate the seasonal dynamics of lakes, CHRIS-PROBA data were acquired in spring, summer and autumn 2002, 2003 and 2004. A first analysis of the data showed that CHRIS radiance data have strong artefacts in along track direction. Standard destriping techniques were not sufficient to correct the data. Therefore, a novel iterative destriping technique was developed and successfully applied to CHRIS-PROBA data. During the CHRIS-PROBA data recording, spectral field measurements and acquisition of in-situ data took place at several test sites. Using these data, chlorophyll algorithms were developed and optimised to the spectral characteristics of the CHRIS sensor. On the basis of simulated CHRIS-PROBA spectra in mode 2 and mode 3, the effect on the chlorophyll estimation will be discussed.