Upgrading the HUSIR Radar for Deep-Space Satellite Imaging

The Haystack Ultra-wideband Satellite Imaging Radar (HUSIR) is a dual-frequency ground-based radar operating at X-band and W-band providing high resolution Inverse Synthetic Aperture Radar (ISAR) imagery of Earth orbiting satellites at 3 cm resolution. An upgrade of the radar hardware is being initiated to extend W-band operation from low Earth to geosynchronous orbit. In this paper we report on the development of a new W-band Gyro TWT transmitter increasing peak transmit power from ~1 kW to ~50 kW and upgrades to the receiver and feed subsystems made necessary by the increased W-band power.