SHIP DETECTION APPROACH BASED ON CROSS-CORRELATION FROM ENVISAT ASAR AP DATA

Abstract

Preliminary results are reported on ship detection using coherence images computed from crosscorrelatingimages of multi-look-processed dual-polarization data (HH and HV) of ENVISAT ASAR. The traditionaltechniques of ship detection by radars such as CFAR (Constant False Alarm Rate) rely on the amplitude data, andtherefore the detection tends to become difficult when the amplitudes of ships images are at similar level as the meanamplitude of surrounding sea clutter. The proposed method utilizes the property that the multi-look images of ships arecorrelated with each other. Because the inter-look images of sea surface are covered by uncorrelated speckle, crosscorrelationof multi-look images yields the different degrees of coherence between the images and water. Thepolarimetric information of ships, land and intertidal zone are first compared based on the cross-correlation betweenHH and HV. In the next step, we examine the technique when the dual-polarization data are split into two multi-lookimages.