Klaus Strübing

Federal Maritime and Hydrographic Agency (BSH)

Postfach 301220 - 20305 Hamburg

Telefon: 40/3190-3220, Telefax: -5032

E-Mail: klaus.struebing@m1.hamburg.bsh.d400.de

For the 1st ERS-1/AO the author was Principal Investigator of the proposal "Use of ERS-1 data for sea ice reconnaissance and operational ice service in the Western Baltic" - d8/PIP.BAL3. Due to an eight years period of only normal to mostly mild winters, no essential ice cover was experienced in the mentioned region and no relevant results could be presented within the time frame valid for the above proposal.

Since 1986/87 it was in the winter 1995/96 that a strong ice season with sufficient and long enough ice coverage of the western sea areas of the Baltic developed. Despite the problem not having furthermore the PI status within the framework of ERS-2, short-term SAR data requests for the area of the western Baltic Sea could be included into the mission plan for the second half of February 1996. Luckily enough, this period fell into time frame of the ERS-1/2 Tandem Mission. As a result a set of not only ERS-1 and ERS-2 SAR scenes but also scenes from ascending and descending orbits of the same areas could be taken. Although it was not possible to receive the data in NRT for operational use, of course also their off-line availability provided valuable general information and knowledge on the specific sea ice conditions in the coastal and sea areas of the western Baltic. The ice conditions were characterized by level and rafted ice, compact ice belts and ice patches and small ice fields of different concentration categories and stages of development. Open sea areas and leads were mostly influenced by higher wind speeds. The various sea ice parameters of interest are evaluated per se and in comparison of the different sensors and orbit modes. The interpretation of the radar signatures could be assisted by NOAA/AVHRR and aircraft SLAR as well as by ground observations.

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry