MOTION STABILIZED GRAVITY GRADIOMETER

摘要

Method and apparatus for measuring gravity gradients directly. Two retroreflectors are caused to experience free flight, and the radiation reflected by these retroreflectors during free flight is directed to a radiation receiver which senses and measures the temporal variations of intensity of the interfering reflected radiation beams. The time rate of change of the frequency of the output signal of the receiver is directly related to the vertical gradient of gravity. The instrument of this invention has means to determine, and if desired correct for, deviations of the optical axis of the instrument from the local vertical, rotational motion of the instrument which will cause undesirable Coriolis accelerations and means to compensate for undesirable horizontal motion. This gravity gradiometer is particularly suitable for use aboard moving platforms such as ships, planes and helicopters.