Design and calibration of a compact low-noise magnetic gradiometer

The paper describes the design, test and calibration of a compact, low-noise magnetic gradiometer developed under contract to ESA (Contract reference: AO/1-6085/09/NL/AF) by the Science and Technology Facility Council, Rutherford Appleton Laboratory (RAL Space), Bartington Instruments and the National Physical Laboratory (NPL). The gradiometer is being developed as a technology pathfinder for a diagnostics payload to characterize magnetic disturbances around space instruments susceptible to magnetic fields and gradients such as the candidate Cosmic Vision mission LISA/NGO. The gradiometer is also to be used in the verification of the magnetic cleanliness of spacecraft and spacecraft subsystems.