Self-calibrating GPS reference station and method

• US 6,140,959 A
• Filed: 03/13/1996
• Issued: 10/31/2000
• Est. Priority Date: 03/13/1996
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Gudat, Adam J., Harrod, Gregory R., Henderson, Daniel E.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): PHAN, DAO LINDA
• Application Number:
  US08/615,349
• Time in Patent Office: 1,693 Days
• Field of Search: 342/357, 342/457, 342/174, 342/357.12, 342/357.06, 701/213, 455/12.1
• US Class Current: 342/357.25
• CPC Class Codes: G01S 19/071 DGPS corrections

Abstract

A self-calibrating Global Positioning System (GPS) reference station and method for operating the reference station. The reference station includes a station frame, a GPS receiver and a controller mounted on the station frame. The controller upon power up, determines if the reference station has been moved and determines a new reference position of the reference station if the reference station has been moved. The GPS receiver is then placed into a reference station mode.

Claims

1. A method for automatically calibrating a Global Positioning System (GPS) satellite reference station, the reference station includes a station frame, a GPS receiver and a controller being mounted on the station frame, the controller being adapted to calibrate the GPS receiver, comprising:

retrieving from the GPS receiver a last reference position estimate;

receiving from the GPS receiver a new position estimate;

comparing said new position estimate to said last reference position estimate; and

,

determining a new reference position estimate if said new position estimate is not within a preset distance of said last reference position.

2. A method, as set forth in claim 1, wherein the step of determining a new reference position includes the steps of:

receiving a series of position estimates from the GPS receiver over a preset time period; and

,

calculating said new reference position as a function of said series of position estimates.

3. A method for automatically calibrating a Global Positioning System (GPS) satellite reference station, the reference station includes a station frame, a GPS receiver and a controller being mounted on the station frame, the controller being adapted to calibrate the GPS receiver, comprising:

placing the GPS receiver in an autonomous mode;

retrieving from the GPS receiver a last reference position;

receiving from the GPS receiver a new position estimate;

comparing said new position estimate to said last stored position estimate;

receiving a series of position estimates from the GPS receiver over a preset time period, calculating a new reference position as a function of said series of position estimates and calculating a new reference position if said new position estimate is not within a preset distance of said last reference position;

programming the GPS receiver with said reference station position; and

placing the GPS receiver in a reference station mode.

4. A self-calibrating Global Positioning System (GPS) reference station, comprising:

a station frame;

a GPS receiver mounted to said station frame;

controlling means for initializing said GPS receiver, retrieving a last reference position from said GPS receiver, receiving a new position estimate from said GPS receiver, comparing said new position estimate to said last reference position;

for determining a new reference position if said new position estimate is not within a preset distance of said last reference position; and

for programming the GPS receiver with said new reference position.

5. A self-calibrating GPS reference station, as set forth in claim 4, wherein said GPS receiver is a Differential GPS receiver adapted to produce position correction signals, and wherein the self-calibrating GPS reference station includes:

a GPS antenna coupled to said GPS receiver;

a radio coupled to said controlling means;

and wherein said controlling means includes means for receiving the correction signals from said GPS receiver and transmitting the correction signals via said radio.