Integrated navigation and communication satellite system
First Claim
1. A satellite system for integrating navigation and communications information, comprising:
- navigational satellite means for providing navigational reference signals;
communications satellite means for receiving transmitted communications signals and re-transmitting communications signals indicative thereof;
transmitting means, in said communications satellite means, for transmitting signals indicative of said navigational reference signals; and
receiver station means for receiving communications signals re-transmitted from said communications satellite means, and comprising;
means, receiving navigational reference signals directly from said navigational satellite means and said indicative navigational reference signals from said transmitting means in said communications satellite means, for performing calculations using both of said reference signals to provide enhanced position and time information for said receiver station means; and
wherein said transmitting means comprises;
means for receiving navigational reference signals directly from said navigational satellite means; and
means for converting said navigational reference signals to indicative navigational reference signals for transmitting to said receiver station means.
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0 Petitions
Accused Products
Abstract
A system and method for improving the accuracy of pseudorange error measurements at a receiving or user station by utilizing a communications satellite as an additional ranging source for providing navigational signal information, wherein the user station, in fixing its position on the Earth, receives a pseudorange signal directly from a GPS satellite and also a pseudorange indicative or pseudorange-error indicative signal from a communications satellite which re-broadcasts, a time tagged, indicative signal to serve as another observable in pseudorange equations computed in the user station. The communications satellite may receive a pseudorange signal directly, or an error indicative signal from an Earth-based station, for conversion into the pseudorange indicative or error indicative signal it transmits. A particular embodiment for incorporation in a communications satellite constellation, such as Globalstar™, involves a reference station, or network of reference stations disposed at appropriate Earth locations, for providing pseudorange error signals from their locations that are collected at a masterstation in a satellite gateway for processing and then transmitting by the gateway to a communications satellite. The satellite converts and re-transmits the processed information to a user station at another Earth location where the received information is used, along with directly received GPS information signals, to enhance the navigational position accuracy of the user station. Thus, an additional ranging source is provided that improves the accuracy, availability, and integrity of the pseudorange measurements.
58 Citations
15 Claims
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1. A satellite system for integrating navigation and communications information, comprising:
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navigational satellite means for providing navigational reference signals; communications satellite means for receiving transmitted communications signals and re-transmitting communications signals indicative thereof; transmitting means, in said communications satellite means, for transmitting signals indicative of said navigational reference signals; and
receiver station means for receiving communications signals re-transmitted from said communications satellite means, and comprising;means, receiving navigational reference signals directly from said navigational satellite means and said indicative navigational reference signals from said transmitting means in said communications satellite means, for performing calculations using both of said reference signals to provide enhanced position and time information for said receiver station means; and wherein said transmitting means comprises; means for receiving navigational reference signals directly from said navigational satellite means; and means for converting said navigational reference signals to indicative navigational reference signals for transmitting to said receiver station means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for integrating satellite navigation and communications information, comprising the steps of:
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locating at least one navigational satellite that produces navigational reference signals; locating at least one communications satellite that receives transmitted communications signals and re-transmits signals indicative thereof; relaying, from said communications satellite, signals indicative of said navigational reference signals; receiving at a receiver station, that receives indicative communications signals from said communications satellite, navigational reference signals directly from said navigational satellite and said indicative navigational reference signals relayed from said communications satellite; and performing appropriate calculations using both of said reference signals to provide enhanced position and time information for said receiver station; and wherein said relaying step comprises; receiving navigational reference signals at said communications satellite directly from said navigational satellite; and converting said navigational reference signals to said indicative navigational reference signals for transmitting to said receiver station. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification