Directivity of wind vectors derived from spaceborne scatterometers

Directional distribution of vectors derived from spaceborne scatterometers such as the ERS-1/AMI scatterometer and ADEOS/NSCAT is investigated to evaluate self-consistency of wind observations. It is shown that scatterometer-derived wind vectors may exhibit systematic directional preference relative to antenna beam directions, which is considered to be caused by imperfections in the geophysical model functions used to retrieve the wind vectors from backscattering measurements. The distribution of wind directions is very sensitive to the errors in the model function, and can be used as an effective measure of self-consistency to validate the model functions and retrieved wind vectors