Satellite Remote Sensing for Lake Monitoring (SALMON)

Map of the chlorophyll a and a phaeophyine a concentrations in Lake Erken using correlation to CASI band 8 (659.0-669.8 nm).

Objectives:

The overall objective of the project is the evaluation of the capabilities of current and forthcoming spaceborne remote sensing for the monitoring of European lake water quality. The this end, the following specific objectives will be targeted:

• interaction with end-users to define their needs for the monitoring of water quality (parameters, accuracy, frequency);
• evaluation of the capabilities of current instruments and methods to fill these needs;
• improvement of the processing methods for remote sensing data including calibration, atmospheric correction, and correction for solar zenith angle;
• acquisition of airborne and in-situ data during campaigns involving instruments similar to the next generation of spaceborne instruments (e.g. hyperspectral passive observation, fluorescence lidar);
• evaluation of the capabilities of these airborne instruments to fill these needs;
• definition of an optimal spaceborne sensor for the purpose of lake water quality monitoring.

The recent activities of the SALMON project in Uppsala during the 5th quarter:

In September, work that was related to the field campaign in August was performed. We collected meteorological data from different sources. An investigation of the possibility of getting a higher accuracy in the GPS measurements by means of the SWEPOS system was also performed, because of the fact that the governmental dGPS system was only functioning sporadically at the time of the fieldwork. Unfortunately the SWEPOS system was not applicable to our GPS data.

In October the first CASI-data from the field campaign was delivered in the form of EXA-byte tapes. A total of approximately 2.5 Gigabyte was collected over Lake Erken and Lake Mälaren including some data from the inner Stockholm Archipelago. Uppsala was the organiser and the distributor of the data to the other CASI data users for this campaign. The image (and spectral) data was delivered rectified and the SALMON image data has been transferred to CD-ROM and the flights over Erken has been mosaicked. When this was done we noticed that the rectification was not adequately done. There were several mismatches which has to be removed in order to get a nice mosaic of Erken. Also there were some problems with the calibration of the images that have to be managed.

Some preparatory studies and classifications of the structures formed by the algae in Lake Erken have been done. These show that it is possible to segment the water area in an unsupervised manner and the result is at least visually very reasonable. It remains to compare the segmentations to what is found in the field data (optical data and water samples).

A steering group meeting was held at JRC, Ispra, Italy in the beginning of October in which Prof. Lindell participated. One of the proposals from the co-ordinator was to prepare some kind of booklet or information gathering on Aquatic Remote Sensing. The responsibility for the synthesis was on CBA and the structure for this booklet and the organisation has been dealt with at CBA.

The literature published or submitted by the Uppsala SALMON Group could be find in the literature list

The SALMON project was finished in May 1999