Flashing Fields! A Preliminary Investigation

Large localized discrepancies are observed between measurements made by ASAR and by the ERS-2 AMI, within 30 minutes of each other over Flevoland, NL. The discrepancies appear to be related to fine details of the observing geometries of the two instruments, specifically the relative Doppler centroids of the two instruments. There is little awareness of such sensitivity and it is not predicted by the models for microwave interaction usually applied to soils and vegetation. The objective of the present investigation is to improve understanding of the phenomenon and examine strategies to mitigate its effects.