Asar App and Apm Image Quality

This paper gives details of the image quality analysis of ASAR alternating polarisation mode APP and APM products performed during the ASAR validation phase. Initially, a description of the analysis methodology and performance assessment tools, image properties and example APP and APM products is given followed by the image quality analysis. This analysis includes format verification, visual inspection of the imagery, impulse response function measurements, cross-polarisation ratio, channel co-registration, equivalent number of looks and radiometric resolution determination, analysis of azimuth ambiguities, localisation accuracy, a preliminary radiometric calibration including the derivation of preliminary calibration constants and noise equivalent radar cross-section measurements.