Patent ID: 7110762
Filing Date: 2006-09-19
Classification: G01C,G01S

Abstract:
1. A base station in communication with a rover unit for use in a Differential Global Positioning System (DGPS), comprising a radio modem transmitter or transceiver having a plurality of pre-defined communication channels, a GPS satellite receiver, and channel selection means for automatically determining which of its pre-defined communication channels is most open to RF traffic and selecting said channel, wherein the communication channels include a Received Signal Strength Indicator (RSSI) and the channel selection means includes an algorithm that measures the RSSI value for each pre-defined communication channel and includes instructions for re-measuring the RSSI values of the pre-defined channels in response to a predefined increase in communication traffic, wherein the openness to transmission of a valid GPS correction information is based on the amount of communication traffic on the channels.