COMPENSATION FOR UNWANTED ACCELERATIONS IN A GRAVITY GRADIOMETER

摘要

A gradiometer is disclosed which has a pair of sensor bars (41, 43) supported in housings (45, 47). Transducers (71) are located adjacent the bars (41, 43) to detect movement of the bars in response to the gravity gradient tensor. At least one of the transducers (71) comprises a first coil (510) and a second coil (516) arranged in parallel and a switch (362) for proportioning current between the coils (510) and (516) so as to create a virtual coil at a position D between the coils (510) and (516).