Sensor system and method

The present invention provides a sensor system and a corresponding sensing method employing the sensor system. The sensor system comprises a sensor (12) having an input (20) and an output (22), a feedback path (16) from the output to the input, and a filter (14; 92) in the feedback path. The filter comprises a narrow band filter, which is tuned or tunable to a respective one of signals that are wanted signals and signals that represent interference signals. The sensor and the filter are arranged so as to alter the relative amplitudes of the wanted signals and the interference signals in order to increase the relative amplitude of the wanted signals and reduce the relative amplitude of the interference signals.