Optimizing σ0 information from the Jason-2 altimeter

A radar altimeter's normalized backscatter, σ0, is used in many oceanographic applications, to infer values of wind speed, wind stress, rain rate and the presence of biogenic slicks. The waveform retracker used to estimate the key geophysical variables for the altimeters on the Jason-1 and Jason-2 satellites shows increased small-scale variability since the problem is ill-conditioned. A simple empirical adjustment to σ0 improves the separability between various parameters and also improves the along-track profiles of σ0. This leads to i) more realistic wind fields, ii) better discrimination of rain events, and iii) improved comparison between the Jason-1 and Jason-2 altimeters during their tandem mission.