Operation of GeoSAR foliage penetration modes in spectrum regulated environment

The GeoSAR FOPEN radar system was developed to provide the US with the capability of generating terrain maps beneath obscuring foliage. In 2003, the GeoSAR system received a Stage 4 license from NTIA permitting its coordinated usage on a secondary, non-interference basis. Recent changes in interpretation of the basis for P-band access has significantly increased the burden in maintain operational readiness. This paper will present the impact of aggressive frequency notching on sensor imagery and subsequent degradation in data quality.