Real time self differential global positioning system and method for a moving station in a local area, and terminal global positioning system using the same

• US 6,704,652 B2
• Filed: 04/25/2002
• Issued: 03/09/2004
• Est. Priority Date: 10/29/2001
• Status: Active Grant

• Current Assignee: Total Soft Bank Ltd.
• Original Assignee: Total Soft Bank Ltd.
• Inventors: Yi, Dong Hyuk
• Primary Examiner(s): Louis-Jacques, Jacques H.
• Assistant Examiner(s): GIBSON, ERIC M
• Application Number:
  US10/131,385
• Publication Number:
  US 20030083817A1
• Time in Patent Office: 684 Days
• Field of Search: 701/214, 701/215, 372/357.02, 372/357.03, 372/357.09, 372/357.1, 372/358
• US Class Current: 701/214
• CPC Class Codes: G01S 19/071 DGPS corrections

Abstract

A terminal Global Positioning System (TGPS) adopting a real-time self Differential Global Positioning System (DGPS) is developed for positioning a moving station in a local area. This TGPS enables not only to minimize the error ranges without any additional expensive transmitting-receiving equipment, but also to calculate an accurate correcting value through a TGPS server. A method of TGPS adopting the real-time self DGPS comprises the steps of: (1) receiving a GPS signal from the moving station containing data of satellite time and pre-measured moving station position, (2) receiving the reference station GPS signals at the TGPS server (3) calculating a correcting value from the moving station at the central control server, (4) calculating an error-corrected real position of the moving station according to the correcting value and position data of moving station at the central server, and (5) positioning the moving station accurately according to the correcting value and the GPS signal of the moving station at the central control server.

Claims

1. A method of terminal Global Positioning System (TGPS) adopting a real-time self Differential Global Positioning System (DGPS) in a local area consisted of a private reference station (10) which has been accurately pre-measured to provide its precise location, the private reference station (10) including a reference station Global Positioning System (GPS) receiver (11) for detecting position via satellites (20˜

23), a moving station (30) including a moving station GPS receiver (31) for detecting position via satellites, and a first wireless modem (32) for transmitting Reference Global Positioning System (RGPS) signals containing position data and satellite time data from the moving station GPS receiver (31), a central control unit (40) including a TGPS server (41), a central control server (42) and a second wireless modem (43) for communicating with the first wireless modem (32) over a short distance, the TGPS server (41) interfacing with the reference station GPS receiver (11), receiving the RGPS signals from the reference station, calculating correction data (X′

0, Y′

0) from the received data, and transmitting the calculated correction data to the central control server (42), the central control server (42) interfacing with the second wireless modem (43), receiving the RGPS signals from the moving station, and calculating the real position of the moving station by correcting the error from the RGPS signals of position data received from the moving station, and a job control data and position data codifying with string, header and separator, the TGPS comprises the processing steps of;

receiving a moving station GPS signal (Mgps_0) at the central control server (42), said moving station GPS signal (Mgps_0) containing data of satellite time (T0) and moving station position (Xm0, Ym0) which are measured via the moving station GPS receiver (MGPS) (31) at a specific position and time,

transmitting said data of satellite time (T0) from the moving station GPS signal to the TGPS receiver (41),

receiving reference station GPS signals (Rgps_-2, Rgps_−

1, Rgps_0, Rgps_1, Rgps_2) at the TGPS server (41), said reference station GPS signals containing satellite time (T0) data and position data (Xr, Yr) which are measured via the RGPS receiver (11) at the private reference station (10) near to said satellite time (T0),

transforming the position data (Xr, Yr) of the private reference station (10) to a local coordinate value from the selected coordinate value (Xr0, Yr0) by the TGPS server (41),

selecting a position data (Xr0, Yr0) of the reference station GPS signal corresponding to said satellite time (T0),

calculating a correcting value (X′

0, Y′

0) according to said selected reference station GPS signal (Rgps_0) and stored actual position data (Xs, Ys) of the reference station at the central control server (42),

transforming the position coordinating value (Xm0, Ym0) of moving station received from the wireless modem (32) of moving station to a local coordinating value by the central control server (42),

calculating an error-corrected real position (Xcm0, Ycm0) of said moving station according to said correcting value and the position data of the moving station at the central control server (42), and

transforming an actual position (Xcm0, Ycm0) of the moving station to an accurate local position coordinating value by the central control server (42).