Case Studies: Application Potential - A Preview

Section 3.7.2 of this review document summarizes the current understanding of ship detection using RADARSAT-1 and the potential of RADARSAT-2. There are two basic approaches to ship detection using SAR: detection of the ship wake signature and detection of the ship target itself. Pervious research using RADARSAT-1 (C-HH) and ERS (C-VV) SAR data has shown that the ship-sea contrast is higher for HH polarizations thus making RADARSAT-1 suitable for target detection. But, HH polarizations clutter is smaller than VV polarization clutter and decreases more readily with increasing incidence angle. For this reason, signatures relating to ship wakes are rarely seen in HH polarization images, however VV polarization provides improved information on sea-state and wake detectability.

For ship surveillance activities, it is expected that a dual polarization SCANSAR wide mode data set composed of VV and VH channels will be optimal. Further it is expected that fully polarimetric data will improve ship target detection and possibly classification although the limited spatial extent of Quad-Pol products will limit its use.

Ship Surveillance	Polarization				Notes
	HH	HV/VH	VV	Quad-pol
Ship detection (ship/sea contrast)	shallow				Current RSAT-1 HH minimizes the sea state return providing good results for ship detection at wind speeds of 7-14 knots
		steeper			Cross pol provides the best contrast at steeper incidence angles; and effectiveness is not degraded in rougher sea conditions
Ship Wake Detection			shallow		ERS-1/2 has shown that wake detection is improved using VV polarization
Ship Surveillance					Optimizing both target (ship) detection and wake detection can be achieved through the dual polarized option of standard RADARSAT-2 modes. This should increase information content for ship surveillance requirements.