Satellite navigation receiver and method

• US 6,437,734 B1
• Filed: 10/11/2000
• Issued: 08/20/2002
• Est. Priority Date: 10/11/2000
• Status: Expired due to Term

• Current Assignee: Furuno Electric Co, Ltd, Seiko Epson Corporation (Seiko Group)
• Original Assignee: eRide, Inc. (Furuno Electric Co, Ltd), Seiko Epson Corporation (Seiko Group)
• Inventors: Woo, Arthur N., McBurney, Paul W.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US09/687,044
• Time in Patent Office: 678 Days
• Field of Search: 342/357.09, 342/357.1, 342/357.15, 342/357.03
• US Class Current: 342/357.62
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/071 DGPS corrections
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/35 Constructional details or hardware or software details of the signal processing chain
• CPC Class Codes: G01S 5/0018 Transmission from mobile station to base station
• CPC Class Codes: G01S 5/0045 Transmission from base station to mobile station G01S5/009 takes precedence

Abstract

A satellite-navigation system comprises an observer platform for collecting signal observations from orbiting navigation satellites. A server platform provides a simplified navigation-satellite constellation almanac, ephemeris, differential correction, and client services. A navigation platform passes information between the observer and server platforms and provides for autonomous position solution computations for a limited time after a periodic call for an aiding data from the server platform. A measurement platform included in the server platform makes static observations of a navigation-satellite constellation and that builds a database of measurement errors and satellite data messages. A health and quality monitor included in the server platform checks the static observations and preventing an inclusion of incorrect information in the database of measurement errors and satellite data messages. A TCP/IP communication link existing at least once between the server and navigation platforms supports an information datapacket format that periodically transfers over the communication link. It reduces the almanac and ephemeris satellite messages at the server platform to a set of simple polynomials that represent a recent satellite position and velocity. These are useful at the navigation platform to compute a current position solution with real-time data from the observation platform. An aiding data with light-weight models is provided by the server platform to the observer platform to eliminate all data storage of almanac and ephemeris, and to permit only fixed-point integer arithmetic to be used to solve for user position at the navigation platform.

Claims

1. A satellite-navigation system, comprising:

an observer platform for collecting signal observations from orbiting navigation satellites;

a server platform for providing a simplified navigation-satellite constellation almanac, ephemeris, differential correction, and client services;

a navigation platform for passing information between the observer and server platforms; and

a polynomial model for reduced data communication volume and reduced computational effort at the navigation platform, and that simultaneously approximates said navigation-satellite constellation almanac, ephemeris, differential correction, and client services;

wherein an aiding data provided by the server platform to the observer platform eliminates all data storage of almanac and ephemeris, and only fixed-point integer arithmetic is used to solve for user position at the navigation platform.

2. The system of claim 1, wherein:

the navigation platform provides for autonomous position solution computations for a limited time after a periodic call for said aiding data from the server platform.

3. The system of claim 1, wherein:

the server platform includes a measurement platform for static observations of a navigation-satellite constellation and that builds a database of measurement errors and satellite data messages.

4. The system of claim 3, wherein:

the server platform includes a health and quality monitor for checking said static observations and preventing an inclusion of incorrect information in said database of measurement errors and satellite data messages.

5. The system of claim 1, further comprising:

a communication link between the server and navigation platforms; and

a communication format presented over the communication link that reduces almanac and ephemeris satellite messages at the server platform to simple polynomials that represent a recent satellite position and velocity useful at the navigation platform to compute a current position solution with real-time data from the observation platform.

6. The system of claim 1, further comprising:

a TCP/IP communication link existing at least once between the server and navigation platforms; and

an information datapacket format periodically presented at least once over the communication link that reduces almanac and ephemeris satellite messages at the server platform to simple polynomials that represent a recent satellite position and velocity which are useful at the navigation platform to compute a current position solution with real-time data from the observation platform.

7. A satellite-navigation system, comprising:

an observer platform for collecting signal observations from orbiting navigation satellites;

a server platform for providing a simplified navigation-satellite constellation almanac, ephemeris, differential correction, and client services; and

a navigation platform for passing information between the observer and server platforms and that provides for autonomous position solution computations for a limited time after a periodic call for an aiding data from the server platform;

a measurement platform included in the server platform for making static observations of a navigation-satellite constellation and that builds a database of measurement errors and satellite data messages;

a health and quality monitor included in the server platform for checking said static observations and preventing an inclusion of incorrect information in said database of measurement errors and satellite data messages;

a TCP/IP communication link existing at least once between the server and navigation platforms; and

an information datapacket format periodically presented at least once over the communication link that reduces an almanac and ephemeris satellite message at the server platform to a set of simple polynomials that represent a recent satellite position and velocity, and which are useful at the navigation platform to compute a current position solution with real-time data from the observation platform;

wherein an aiding data with light-weight models provided by the server platform to the observer platform eliminate all data storage of almanac and ephemeris, and permit only fixed-point integer arithmetic to be used to solve for user position at the navigation platform.

8. A satellite-navigation system, comprising:

an observer platform for collecting signal observations from orbiting navigation satellites;

a server platform for providing a simplified navigation-satellite constellation almanac, ephemeris, differential correction, and client services; and

a computationally light-weight navigation platform for passing information between the observer and server platforms;

wherein an aiding data provided by the server platform to the observer platform eliminates all data storage of almanac and ephemeris, and only fixed-point integer arithmetic is used to solve for user position at the navigation platform; and

wherein, the navigation platform solves user position only to a quantization level, and the server platform differentially corrects such solution and computes quantization as though it is just another error source to arrive at a more precise user position fix.