Flown onboard Radarsat (Canada).

Applications: ice; coastal surveillance; coastal and open oceans; cartography; land use; geology; environmental monitoring; hydrology; agriculture; forest.

SAR is an active microwave instrument that sends signals to Earth and processes the return signal. An advantage of using this type of system is the ability to acquire imagery day and night, and through clouds.

More information:

http://www.spaceimaging.com or
http://www.space.gc.ca/csa_sectors/earth_environment/radarsat/default.asp

This area shows the coast of Wales shortly after the oil tanker began leaking. The tanker has been moved to the port facilities at the river's mouth. ©1995 Canadian Space Agency (CSA). Image received by the Canada Centre for Remote Sensing (CCRS), and processed and distributed by RADARSAT International.
(source: http://www.space.gc.ca/csa_sectors/earth_environment/radarsat/radarsat_info/early_images/default.asp).