The Netherlands – ASAR - 19, 23, 26 April 2002

This Envisat radar composite image was taken over the city of Zwolle in Holland. Running through the centre of the image is the Ijseet River with the city flanking its western bank in the centre of the image. The green area on the opposite bank represents woodlands. Further to the west, the bright green area is a natural clearing.

To the north of the image the brightly coloured patchwork effect is caused by agricultural land. The different field colours represent different crops. The bright blue region to the north is Lake Beulakerwidje. The city of Meppel is to the northeast.

ASAR imagery offers an opportunity to monitor many aspects of the Earth’s surface (agriculture, forestry, disaster management, hydrology, cartography, geology). The return signal depends on the radar system’s parameters (wavelength, polarization, incidence angle, viewing geometry) and the target parameters (dielectric constant, humidity, surface roughness, vegetation cover).

Technical Information:
Instrument: Advanced Synthetic Aperture Radar (ASAR)
Mode: IMP
Acquisition date: 19.04.02 (IS2), 23.04.02 (IS1), 26.04.02 (IS2) as RGB
Orbit number: 00756, 00770, 00813 as RGB
Orbit direction: Descending, Ascending, Ascending as RGB
Polarisation: VV
Resolution: 25 m