Abstract
This paper describes in-orbit modal test using sine excitation. As space structure is larger, in-orbit modal test accuracy is need to avoid vibration coupling with control subsystem. Impulse and random excitations are popular with the past in-orbit modal tests. The purpose of using sine excitation is to improve frequency response function. In the test, it is important to determine where excitation force is enough or not. We focus on accelerometer noise level to determine excitation force. A numerical simulation shows that excitation force is enough to give the required acceleration.
