US Patent 9395465 Gravity and/or acceleration measurements using dual interferometer configurations

An apparatus for estimating gravitational properties includes an optical source, a first interferometer including a fixed reference reflector and a first reflector coupled to a first moveable mass, a second interferometer including the fixed reference reflector and a second reflector coupled to a second moveable mass, a first detector configured to detect a first interference pattern generated by the first interferometer, and a second detector configured to detect a second interference pattern generated by the second interferometer. The first mass is configured to move a first amount in response to a change in gravitational force, and the second mass is configured to move a second amount in response to a change in gravitational force, the second amount being smaller than the first amount. The apparatus also includes a processor configured to estimate the change in gravitational force based on a combination of the first and second interference patterns.