摘要 |
Methods and apparatuses which use satellite position system (SPS) reference receivers. In one example of the invention, a plurality of SPS reference receivers, such as Global Positioning System (GPS) reference receivers, each having a known position, are dispersed over a geographical region. Each of the SPS reference receivers transmits into a communication network, a representation of at least a portion of a satellite navigation message, such as satellite ephemeris data, received from SPS satellites in view of the particular SPS reference receiver. A plurality of digital processing systems, such as a first and a second digital processing systems, are coupled to the communication network to receive the satellite ephemeris data which is transmitted through the communication network.
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