A DUAL-FREQUENCY MM-WAVE RADIOMETER ANTENNA FOR AIRBORNE REMOTE-SENSING OF ATMOSPHERE AND OCEAN

Accurate multiwavelength radiometric remote sensing of the ocean and t he atmosphere from an aircraft requires antennas with the same beamwid th at the various frequencies of operation. An offset antenna was desi gned with a pressure-compensating corrugated feed horn to meet this cr iterion. A specially designed fairing was incorporated into the antenn a to optimize the aerodynamics and minimize the liquid build up on the antenna surfaces. The antenna has two positions, the zenith (up) posi tion and the nadir (down) position. The far-field pattern results show that the antenna beamwidths at 23.87 and 31.65 GHz agree well with de sign criterion. This antenna was recently used in an ocean remote-sens ing experiment and performed according to expectations.