Space Shuttle Ku-band radar

The Shuttle Ku-band system is a dual mode system that can be operated either as a two-way communications with the ground via the Tracking and Data Relay Satellite System or as a radar system to track another spacecraft. The radar mode is used during rendezvous and proximity operations to provide range, range rate, angle, and angle rate information to the on-board Shuttle navigation system. Target detection at short range can be determined from any single transmitted pulse that crosses the required threshold whereas at long range, detection is based upon the integration of all the transmitted pulses from a complete data cycle. Once a target is detected, the radar is switched to the track mode and performs range, range rate, and/or angle tracking. This paper discusses the concepts and techniques utilized in the search and track modes, including a description of the waveforms and how signal processing is performed.