Multi-channel and multi-polarisation ship detection

Norway's large ocean areas in the North require efficient methods to detect vessels in the High North. Radar satellites in orbit today offer dual- or quad-polarised data, which ease the task of detecting vessels in a SAR (Synthetic Aperture Radar) image. FFI has developed an automatic ship detection tool, AEGIR, which uses all polarisation channels to detect vessels. Combining the available channels increases the ship to sea contrast. 19 RADARSAT-2 quad-polarisation images have been run through AEGIR, and it showed that cross-polarisation and (HH-VV)*HV are best for ship detection for all incidence angels. HH-polarisation works well for high incidence angels. RADARSAT-2 offers new high resolution wide modes, which makes it possible to use high resolution and quad-pol images for operational ship detection.