Differential navigation system for remote mobile users
First Claim
1. A differential naviagtion system applicable to mobile users and covering a wide geographic area, including remote regions, which comprises:
- a reference receiver of known location, situated o more than 500 miles from the user, which reference receiver receives information from a navigation information service, computes differential data of the location of said reference receiver with respect to the information from said navigation service and communicates said computed differential data to a transmitting unit;
a transmitting unit that transmits, using spread spectrum techniques, sid computed differential data to a commercial geosynchronous earth satellite relay;
a commercial geosynchronous earth satellite that receives and relays the transmitted signal through a linearly polarized transponder;
a non-directional circularly polarized non-stabilized antenna at the user that receives the relayed signals;
means for receiving navigation information at the user from the navigation information service; and
processing means at the user that computes the location of the user using the navigation information and said computed differential data.
2 Assignments
0 Petitions
Accused Products
Abstract
A differential navigation system applicable to mobile users and covering a wide range geographic area, including remote regions. A reference receiver of known location tracks a navigation information service, computes differential data with respect to that information and communicates the data to a transmitting unit. The transmitting unit transmits differential data via a commercial geosynchronous earth satellite relay to a mobile user located no more than 500 miles from the reference receiver, but possibly located in a remote region. The mobile user receives the relayed signal with a non-directional, circularly polarized, non-stabilized antenna. Reception at a sufficient data rate with sufficient reliability is made possible by formatting the differential data using spread spectrum techniques.
239 Citations
11 Claims
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1. A differential naviagtion system applicable to mobile users and covering a wide geographic area, including remote regions, which comprises:
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a reference receiver of known location, situated o more than 500 miles from the user, which reference receiver receives information from a navigation information service, computes differential data of the location of said reference receiver with respect to the information from said navigation service and communicates said computed differential data to a transmitting unit; a transmitting unit that transmits, using spread spectrum techniques, sid computed differential data to a commercial geosynchronous earth satellite relay; a commercial geosynchronous earth satellite that receives and relays the transmitted signal through a linearly polarized transponder; a non-directional circularly polarized non-stabilized antenna at the user that receives the relayed signals; means for receiving navigation information at the user from the navigation information service; and processing means at the user that computes the location of the user using the navigation information and said computed differential data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A differential navigation method applicable to mobile users and covering a wide geographic area, including remote regions, which comprises:
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receiving at a reference receiver of known location navigation information from a navigation information service; computing differential data of the location of said reference receiver with respect to the navigation information from said navigation service; communicating computed the differential data to a transmitting unit; transmitting, using spread spectrum techniques, the computed differential data to a commercial geosynchronous earth satellite relay; relaying the transmitted signals through a linearly polarized transponder on the earth satellite; receiving with a non-stable circularly polarized non-directional antenna, located at a user no more than 500 miles from the reference receiver, the signals relayed by the earth satellite transponder; receiving at the user navigation information from the navigation information system; and computing at the user the location of the user using the navigation information and the computed differential data. - View Dependent Claims (10, 11)
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Specification