Abstract: A sensor system for determining parameters of a source of a potential-energy field. The system has a sensor array for sensing a property of the potential-energy field generated by the source, with a first sensor at a first position and a second sensor at a second position. The first and second sensor each have a sensor output for outputting a sensor signal representing the sensed property. A signal processor can determine the sensed property as a function of the position of the at least one first sensor and the at least one second sensor. A correlator is connected to the signal processor and arranged to correlate the determined result to a predetermined result derived for a template source positioned at a predetermined position and/or orientation with respect to the sensor array. A calculator is connected to the correlator. The calculator can determine the parameter from the correlation result.