Method and system for using altitude information in a satellite positioning system

• US 6,307,504 B1
• Filed: 03/22/2000
• Issued: 10/23/2001
• Est. Priority Date: 05/05/1998
• Status: Expired due to Term

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Inventors: Sheynblat, Leonid
• Primary Examiner(s): Phan, Dao
• Application Number:
  US09/532,403
• Time in Patent Office: 580 Days
• Field of Search: 342/357.01, 342/357.06, 342/462, 342/357.11, 701/213, 455/422
• US Class Current: 342/357.33
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 19/50 whereby the position solution is constrained to lie upon a particular curve or surface, e.g. for locomotives on railway tracks

Abstract

A method and apparatus for determining a position of a mobile satellite positioning system (SPS) receiver. In one example of a method, a cell object information is determined; this cell object information comprises at least one of a cell object location or a cell object identification. An altitude is determined from the cell object information which is selected based upon a cell site transmitter which is in wireless communication with a cell based communication system which is coupled to (and typically integrated with) the mobile SPS receiver. The position of the mobile SPS receiver is calculated using the altitude which is determined from the cell object information. In another example of a method, an altitude pseudomeasurement is determined from an estimate of an altitude of the mobile SPS receiver. This estimate of the altitude may be from a cell based information source in a cell based system or may be an average altitude of the area of radio coverage of a wireless basestation in the non-cell based system. The altitude pseudomeasurement may be used as a redundant measurement with fault detection and isolation techniques to determine whether at least one pseudorange has a faulty condition. Alternatively (or in addition), a comparison of the estimated altitude to a calculated altitude determines a condition of at least one pseudorange between an SPS satellite and the mobile SPS receiver. In one embodiment of this example, the position is determined from a position solution algorithm, and if the condition is a first state (not a fault state) the at least one pseudorange is used in the position solution algorithm

Claims

1. A method for determining a position of a mobile satellite positioning system (SPS) receiver, said method comprising:

determining a plurality of satellite pseudoranges between said mobile SPS receiver and a corresponding plurality of satellites;

determining at least one non-satellite pseudomeasurement;

determining a condition of at least one of said plurality of satellite pseudoranges.

2. A method as in claim 1 wherein said non-satellite pseudomeasurement is one of an altitude pseudomeasurement or a cellular pseudorange.

3. A method as in claim 2 wherein said condition is determined from said non-satellite pseudomeasurement being a redundant measurement.

4. A method as in claim 3 wherein said condition is determined using SPS fault detection and isolation techniques.

5. A method as in claim 4 wherein said corresponding plurality of satellites comprise a plurality of satellites orbiting in space around the earth.

6. A method as in claim 4 wherein said position is determined from a position solution algorithm and wherein if said condition is a first state said at least one of said plurality of satellite pseudoranges is used in said position solution algorithm.

7. A method as in claim 6 wherein if said condition is a second state, said at least one of said plurality of satellite pseudoranges is not used in said position solution algorithm.