ON SEA ICE CHARACTERISATION BY MULTI-FREQUENCY SAR

摘要

By means of polarimetric target decomposition, quad-polrnSAR data of sea ice is analysed at two frequency bands.rnIn particular, the non negative eigenvalue decompositionrn(NNED) is applied on L- and C-band NASA/JPL AIRSARrndata acquired over the Beaufort sea in 2004. The decompositionrnseparates the scattered radar signal into threerntypes, dominated by double, volume and single bouncernscattering respectively. Using ground truth derived fromrnRADARSAT-1 and meteorological data, we investigaternhow the different frequency bands compare in terms ofrnthese scattering types. The ground truth contains multirnyear ice and three types of first year ice of different agernand thickness.rnWe find that C-band yields a higher scattered intensityrnin most ice and scattering types, as well as a more homogeneousrnintensity. L-band on the other hand yieldsrnmore pronounced deformation features, such as ridges.rnThe mean intensity contrast between the two thinnest icerntypes is highest in the double scattering component of Cband,rnalthough the contrast of the total signal is greater inrnL-band. This may indicate that the choice of polarimetricrnparameters is important for discriminating thin ice types.