methods that test multibeam satellite communication systems , including its antennas and transponders . the methods use input power telemetry and output noise power to test satellite transponders and antennas while the satellite is in orbit . one method that tests a satellite receive antenna employs at least two earth stations , one for rf testing and one for telemetry and commanding , with each providing a backup for the other . other methods may use one or more earth stations to perform testing . methods are disclosed that generate receive antenna pattern measurements , transmit pattern measurements , input chain frequency response curves , input chain transfer curves , and output chain frequency response curves .