We have been developing a new type of gravity gradiometer that employs technologies of laser interferometer. In the gravity gradiometer, differential accelerations between two test bodies, freely falling at different heights in the local gravitational fields, are measured by a Michelson interferometer. Our preliminary laboratory experiment shows that the gravity gradiometer has a resolution of a few μGal/m. By incorporating some improvements for practical use, the gravity gradiometer could be used for various researches in the fields of geodesy and geophysics. We report its working principle and the current status of the development of the gravity gradiometer.
