Method and apparatus for determining the geographic location of a device
View Patent ↗A method and apparatus for determining the location of a device from signals provided by a plurality of satellites. A device receives a first plurality of signals comprising one signal from each of a first plurality of satellites and determines a first location of the device as a function of the first plurality of signals. The device then determines a second location thereof as a function of a second plurality of signals if the first location is not within a predetermined threshold. The second plurality of signals is a first subset of the first plurality of signals.
1. A method for determining the location of a device comprising the steps of:
(a) receiving a plurality of signals from a plurality of satellites;
(b) generating estimates of a location of the device using each different combination of the plurality of signals while leaving out N signal from the received signals; and
(c) selecting an estimate as defined by a quality of each of the combinations,
wherein N is a positive integer.
2. The method of claim 1 wherein a cardinality of the plurality of signals is at least four.
3. The method of claim 1 wherein the satellites are part of a Global Navigation Satellite System (“GNSS”).
4. The method of claim 3 wherein the GNSS is selected from the group consisting of: Global Positioning System (“GPS”), Galileo, GLONASS, and Quasi-Zenith Satellite System (“QZSS”).
5. The method of claim 1 wherein the quality is a function of a sum of the squared residuals.
6. The method of claim 1 wherein the device is a mobile unit.
7. The method of claim 6 wherein the mobile unit is selected from the group consisting of: cellular telephone, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.
8. The method of claim 6 wherein the mobile unit receives signals from a cellular network.
9. The method of claim 8 wherein the estimate of a location of the device is a function of signals provided by the cellular network.