| 摘要 |
<p>Apparatus for receiving ranging signals (e.g. signals from Grobal Positioning System satellites) has a receiver coupled to a plurality of spaced antennas (10). The receiver includes a signal combiner (62) which receives, from a processing circuit, signal components individually representative of a characteristic of th received ranging signals (e.g. signal-to-noise ratio) at a respective antenna and weights the said compenents to produce a range estimate of improved accuracy in difficult reception conditions. In one embodiment the receiver includes a common i.f. channel which filters a combination signal representative of all the incoming signals in order substantially to maintain phase coherence between the incoming signals, yielding improvements in carrier phase measurement and discrimination.</p> |
