This document describes the visualization software for the measurement space and Geophysical Model Function for use with ERS and ASCAT data. The visualization software is developed in IDL for the OSISAF [FIGA 2004]. A 3D measurement space is defined in which the three coordinates correspond to a sigma-triplet, so (x, y, z) = (sigma_fore, sigma_aft, sigma_mid). See also [STOFFELEN 1998]. The Geophysical Model Function (GMF) is represented by a cone-shaped surface with mirror symmetry in the sigma-fore=sigma-aft plane. The ice line is lying in the sigma_fore=sigma_aft plane. The GMF can be shown, as well as the ice line and measurement triplets in sigma-space. The use can choose between linear or logarithmic scale, as well as representation in z-space, a transformation of the sigma-space. For 2D visualization the use can select the plane on which the 3D visualization is projected. Measurement points within a certain distance from this plane are shown. The use can provide the value of this distance.
JA Verspeek. User Manual Measurement Space Visualisation Package
2006, KNMI, 2006