Ground Simulation Test Method for Relay Time Delay of Queqiao-2

This paper proposes a ground test method for measuring the relay forwarding delay of Queqiao-2. By constructing an equivalent satellite-ground transmission channel, the method enables precise measurement of the regenerative forwarding delay. A closed-loop calibration procedure is incorporated into the test system to eliminate the effects of equipment delay and transmission path delay. This approach effectively overcomes limitations of existing methods, such as significant errors in segmented testing, stringent requirements for high-precision time synchronization, the need for extensive test equipment, and difficulties in simulating true environments.Verified through ground tests and on-orbit validation, the method is operationally simple and offers high delay measurement accuracy. It provides strong support for evaluating and optimizing the Queqiao-2 communication system and serves as a valuable reference for measuring telecommand transmission delays in other satellites, demonstrating significant engineering value.