Satellite vibration measurements with an autodyne CO₂ laser radar

Abstract

Vibration signatures of the Low Power Atmospheric Compensation Experiment satellite were obtained with a ground-based CO(2) laser radar. The laser radar operated in a cw mode and used autodyne receivers to extract relative target velocity information between a germanium retroreflector located at the base of the satellite and a retroreflector array located at the tip of an extended forward boom. Time-frequency analysis algorithms were applied to the vibration data to investigate the correlation between excitations and modal structure. The resultant analysis suggests that vibration modes of an on-orbit spacecraft can be suppressed with simple open-loop techniques.