Navigation device and method
First Claim
1. A method of determining a position of a navigation device, the method comprising the steps of:
- receiving a plurality of GPS signals from a plurality of GPS satellites,determining range information from timing information forming part of said signals, together with identification information, specific to each of said satellites,attempting to receive and store entire ephemeris data payloads additionally forming part of each said signals and being specific to each of said satellites,establishing a communication with a proximate device using a wireless communication protocol,determining whether said proximate device has already stored said ephemeris data, or specific parts thereof, relating to satellite position, for the identified satellites,requesting and receiving said ephemeris data or specific parts thereof for said identified satellites,causing said navigation device subsequently to determine its current location using both range information and wirelessly received ephemeris data specific to said satellites for which said range information has been determined.
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Accused Products
Abstract
A method of determining the position of a navigation device when only relatively poor GPS signals are available is described, together with a navigation device capable of determining its current location in such conditions. The method comprises the steps of receiving a plurality of GPS signals from a plurality of GPS satellites, determining range information from timing information forming part of said signals, together with identification information, specific to each of said satellites, attempting to receive and store the entire ephemeris data payloads additionally forming part of each said signals and being specific to each of said satellites.
40 Citations
10 Claims
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1. A method of determining a position of a navigation device, the method comprising the steps of:
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receiving a plurality of GPS signals from a plurality of GPS satellites, determining range information from timing information forming part of said signals, together with identification information, specific to each of said satellites, attempting to receive and store entire ephemeris data payloads additionally forming part of each said signals and being specific to each of said satellites, establishing a communication with a proximate device using a wireless communication protocol, determining whether said proximate device has already stored said ephemeris data, or specific parts thereof, relating to satellite position, for the identified satellites, requesting and receiving said ephemeris data or specific parts thereof for said identified satellites, causing said navigation device subsequently to determine its current location using both range information and wirelessly received ephemeris data specific to said satellites for which said range information has been determined. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. (canceled)
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9. (canceled)
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10. A navigation system, comprising:
a processor, a memory, a graphical display, a GPS signal antenna, wherein said antenna is arranged to receive a plurality of GPS signals from a plurality of GPS satellites, wherein said processor is arranged to determining range information from timing information forming part of said signals, together with identification information, specific to each of said satellites wherein said memory is arranged to store said information and causing the storing of entire ephemeris data payloads additionally forming part of each said signals and being specific to each of said satellites, and wherein said system is provided with a second wireless signal transmission and reception means by virtue of which a communication with a proximate device can be established using a wireless communication protocol, wherein said processor is further arranged to interrogate said proximate device to determining whether said proximate device has already stored said ephemeris data, or specific parts thereof, relating to satellite position for satellites having identification information previously stored in said memory, said processor additionally causing a request signal to be issued and subsequently receiving said ephemeris data or specific parts thereof for said identified satellites by means of which, in conjunction with previously stored range information, said system can determine its current position.
Specification