Oslo

The multitemporal ERS-1 SAR scene represents about 100 by 100km and is composed of:
Red: 9500/2403 10 May 1993 time: 10:24
Green: 7496/2403 21 Dec 1992 time: 10:24
Blue: 10502/2403 18 July 1993 time: 10:24
The centre of Oslo is just visible at the top edge of the image. There are two factors that have shaped this landscape, which mainly is part of the very old scandinavian shield. The first are tectonic movements that fractured the cristalline rock in many directions, giving way to erosion forces that result into a rugged topography but with clear linear features. And the second factor were the glaciers whose carving force strongly contributed to the to-days shape of the landscape.
The colours in the multitemporal image are explained by the changes occured between the different acquisition dates. The woods, mostly coniferous, have not changed and therefore appear in grey. However in the higher area to the west the green colour indicate a dry snow cover on the 21 December 1992. The other colours indicate cultivated areas or pasture land in different growing stages. There seems to be little backscatter contribution from the July-acquisition (blue). This could be explained by the fact that fodder grass has been cut throughout the area and that there was a longer period of dry weather.

(ERS Data Utilization Section, ESA/ESRIN)

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