Amsterdam, The Netherlands

On 9 and 10 May the tracks of ERS-1 and ERS-2 allowed the SAR antennas of both satellites to cover the northwestern part of the Netherlands Provided by

On 9 and 10 May the tracks of ERS-1 and ERS-2 across central Europe allowed the SAR antennas of both satellites to cover the northwestern part of the Netherlands. The image stretches roughly from Den Helder (just off the top edge of the picture) across Amsterdam (in the centre) to Utrecht and The Hague (at the bottom edge on the left); slightly to the right above the latter, between Katwijk and Noordwijk-aan-Zee, there are a number of light reflections from the buildings at ESTEC. Also clearly distinguishable are the Utrecht-Amsterdam motorway and the Noordzeekanaal linking Amsterdam and the Ijsselmeer with the North Sea.

This multitemporal image was obtained by superimposing the ERS-1 date (extracted as blue) with those from ERS-2 (in green). To emphasize even further the difference between the two days, an "artificial" red extract was added that shows the differences in intensity (due to technical causes) between the two SAR systems; as a result, the land mass appears mainly in shades of red. Particularly striking are the uniformly blue areas in the southwestern Ijsselmeer; on the second day the west-northwesterly wind had lessened markedly, so that the wave patterns in these areas differ. As it had rained in the hours before the data were gathered on 10 May, the increased dampness of the soil caused greater backscatter of the radar signal during the second overpass.

Image dates:

• Blue channel: ERS-1 image (9 May 1995);
• Green channel: ERS-2 image (10 May 1995);
• Red channel: contrast enhancement of the two proceeding images (principal components).

Resolution: 25 meters

Size: 100 x 100 km

Weather information at Flevoland (Lelystadt).

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