Shuttle rendezvous radar performance: evaluation and simulation

The authors describe the performance evaluation and simulation of the Ku-band shuttle rendezvous radar. Computer simulation, using the radar cross section for specific spacecraft, provided an estimate of rendezvous radar range performance for that spacecraft. The radar cross section model included smooth metallic surfaces, rough surfaces, and shadowing effects, as well as phase differences due to different path lengths to target other elements. Other parameters included position of the target with respect to the shuttle, relative motion between the radar and the target, and the shuttle and target attitudes. Systematic testing on the White Sands Missile Range (WSMR), using helicopters and balloons and the range radars and cinetheodolites, validated the model and established confidence in the ability of the system to provide the relative position and rate information needed for shuttle work with other spacecraft. Shuttle mission experience of eight flights on Challenger, two on Columbia, and six on Discovery through 1985 confirmed the value of the computer model and missile range tests and showed the reliability of the Ku-band system.<>