Equipment and a method by which power consumed by a ranging receiver (12) is reduced without appreciably impairing performance of the GPS receiver (12), the method including: a step (21) in which a controller (15) reads sensor signals provided by a motion sensor (14) mechanically coupled to the ranging receiver (12); and a step (22) in which the controller (15) powers down selected components of the ranging receiver (12) based on whether the sensor signals indicate only at most insubstantial motion of the ranging receiver (12). The motion sensor is advantageously a motion sensor constructed using MEMS technology, but at any rate is of a type using so little power as to provide a power savings when used according to the invention, i.e. when it is always on and at least partially based on its sensor signals, the ranging receiver (12) is sometimes at least partially turned off.