Sea Surface Scanning for Monitoring Calibration and Stability of the NCAR Airborne W-Band Radar

A new airborne W-band radar has recently been deployed by the National Center for Atmospheric Research. During the CSET experiment, this radar collected multiple sets of scanning data of the ocean surface, and during a recent test program, the aircraft flew what were called “conical scans” (full circle, banked turns, with the radar maintaining a constant off-nadir angle) over the ocean to examine the consistency of surface return with varying wave orientation. These various scans were done with a desire to develop basic scanning strategies that would enable routine monitoring of radar system stability, a vital concern since the radar is pod-mounted and subject to extreme environmental changes.

The ocean surface has been regularly used as a calibration proxy for airborne and space-borne radars. A difference here is that the NCAR radar is fully scanning in the cross-track plane, with pitch and roll compensation. This allows testing of various scan techniques, with the goal of optimizing data collection for stability monitoring, while minimizing impact on the scientific goals of an experiment. Results of past stability monitoring will be presented, with a suggestion for an optimal scan strategy.