Oil Spill Detection and Mapping
The presence of oil on water causes clutter suppression over the area of the spill, resulting in attenuation of the BRAGG scale waves and reduced signal return to the sensor. On the image an oil spill will have a darker tone than the surrounding water. Wind shadows near land, regions of low wind speed, natural surfactants and grease ice can be mistaken for oil spills and ancillary or multi-temporal information is needed to discriminate the oil spill from other phenomena.

RADARSAT beam mode - Optimum beam mode depends on the size of the oil spill (if known) and area of coverage required. Lower resolution beams will reduce oil spill detection but may be better if large area coverage is required.

RADARSAT incidence angle - Steep incidence angles were originally recommended so as to maintain a high ocean clutter-to-noise ratio for signal suppression over an oil spill. With the better than expected noise performance, higher incidence angle modes can be considered.

Look direction - If the area to be imaged is within proximity of a water-land interface, choose a look direction that will image the area of interest in the near half of the swath so as to avoid image quality problems. Look direction is not a critical factor for open ocean areas.

When to acquire RADARSAT data - Data is normally acquired as part of routine surveillance activities of ship traffic, as part of coastal zone monitoring and in response to an emergency disaster. A critical factor affecting the success of imaging an oil spill is wind speed. Oil spills break up and disperse under higher wind speeds.