Satellite position measurement system

• US 6,865,484 B2
• Filed: 04/10/2002
• Issued: 03/08/2005
• Est. Priority Date: 04/11/2001
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Topcon
• Original Assignee: Kabushiki Kaisha Topcon, Mitsui & Company Limited
• Inventors: Kobayashi, Yuji, Mori, Masakazu, Miyasaka, Koji, Takasu, Kenichi, Sakaki, Kazuyuki
• Primary Examiner(s): Camby, Richaerd M.
• Application Number:
  US10/343,916
• Publication Number:
  US 20030154026A1
• Time in Patent Office: 1,063 Days
• Field of Search: 701/213, 701/214, 701/215, 342/357.01, 342/357.03, 342/357.06, 342/357.12, 342/357.13, 342/357, 342/358, 342/357.02
• US Class Current: 701/213
• CPC Class Codes: G01S 19/072 Ionosphere corrections
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry

Abstract

A GPS positioning system that has: at least one mobile station to measure a positional coordinate by receiving radio wave from a satellite; a plurality of fixed stations that have predetermined positional coordinates and receive radio wave from the satellite; and arithmetic processing means, which is connected with at least one mobile station and a plurality of fixed stations via communication, and that transmits correction data suitable for the mobile station to the mobile station based on positioning data transmitted from the mobile station.

Claims

1. A GPS positioning system, comprising:

at least one mobile station for kinematic positioning, that measures a positional coordinate by receiving radio wave from a satellite;

a plurality of fixed stations each having predetermined positional coordinates and receiving radio wave from the satellite; and

arithmetic processing means connected with the mobile station and the fixed stations via communication, wherein geoid correction data suitable for the mobile station are transmitted to the mobile station on the basis of positioning data transmitted from the mobile station.

2. The GPS positioning system according to claim 1, wherein the arithmetic processing means comprises means for transmitting reference positioning data from an appropriate one of the fixed stations, which is selected out of a plurality of reference fixed positioning means, on the basis of the positioning data transmitted from the mobile station, together with the geoid correction data.

3. The GPS positioning system according to claim 1, wherein the mobile station includes an antenna and a receiver which are movable.

6. The GPS positioning system according to claim 2, wherein the arithmetic processing means further comprises means for determining whether or not the mobile station is at least a predetermined distance away from each of the fixed stations, and for also outputting ionospheric data and weather data to the mobile station together with the reference positioning data and geoid correction data, in that event.

7. The GPS positioning system according to claim 6, wherein the ionospheric data and the weather data are not output to the mobile station when the mobile station is determined to be closer than the predetermined distance away from at least one of the fixed stations.

4. A data server for GPS positioning, comprising:

a communication interface that receives positioning data from a mobile station for kinematic positioning, whose positional coordinate is measured by receiving radio wave from a satellite;

a line interface whose positional coordinate is fixed at a known point, and that receives positioning data from a plurality affixed stations that receive radio wave from the satellite;

storage means that stores data regarding correction; and

arithmetic processing means that reads suitable geoid correction data from the storage means and transmits the geoid correction data to the mobile station on the basis of the positioning data received via the communication interface.

5. The data server for GPS positioning according to claim 4, wherein the mobile station includes an antenna and a receiver which are movable.

8. A GPS positioning method comprising:

a) placing a mobile station at a reference point, and establishing a communications link with a data server disposed at another location;

b) performing single positioning by the mobile station receiving radio waves from a plurality of GPS satellites while the mobile station is moved to different positions, and by the mobile station transmitting positioning data obtained from the single positioning to the data server via the communications link;

c) receiving, by the data server, the single positioning data transmitted by the mobile station via the communications link;

d) receiving by the data server, correction positioning data which is obtained by receiving radio waves from the GPS satellites, from a plurality of fixed stations that are fixed in position at fixed positional coordinates;

e) selecting, by the data server, one of the plurality of fixed stations as an appropriate fixed station for the mobile station, the selecting being based on the positioning data transmitted by the mobile station to the data server;

f) transmitting, by the data server to the mobile station as reference data at a point of positional analysis, the correction positioning data obtained from the one of the plurality of fixed stations; and

g) at a same time as step f), transmitting, by the data server to the mobile station, geoid correction data relevant to the positioning data of the mobile station; and

h) computing, by the mobile station, higher-accuracy position information based on the geoid correction data and the correction positioning data of the one of the fixed stations.