Global positioning system and global positioning apparatus

• US 6,674,402 B2
• Filed: 10/07/2002
• Issued: 01/06/2004
• Est. Priority Date: 05/31/2000
• Status: Expired due to Term

• Current Assignee: MiTAC International Corporation (MiTAC Holdings Corp.)
• Original Assignee: Magellan Systems Japan, Inc., Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Magellan Corporation (Thales SA)
• Inventors: Hirata, Seiichiro, Lyusin, Sergy V.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US10/265,252
• Publication Number:
  US 20030030584A1
• Time in Patent Office: 456 Days
• Field of Search: 342/357.02,357.08,357.12,357.06
• US Class Current: 342/357.62
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: G01S 19/254 relating to Doppler shift of satellite signals
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/29 carrier including Doppler, related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 5/0045 Transmission from base station to mobile station G01S5/009 takes precedence

Abstract

A Global Positioning System carries out Doppler correction of a C/A code sequence after a frequency conversion, and calculates a pseudo range by performing correlation calculation between the C/A code, which is obtained by summing up the C/A code sequence beginning from a polarity inversion boundary determined at a correlation peak detecting step ST10, and a C/A code generated in a GPS terminal. When a received electric field detected by a received electric field intensity detector 11 is good, the current position is determined from the pseudo range and the navigation data extracted by the GPS terminal itself, whereas when the received electric field is poor, the current position is determined from the pseudo range and the navigation data sent from an external apparatus.

Claims

1. A GPS positioning method for determining a pseudo range between a satellite and a GPS terminal removed from an external apparatus, comprising the steps of:

determining a delay time by correlation calculation using a C/A code of a GPS signal received from the satellite;

determining a range in which the pseudo range is included based on a distance between the satellite and the external apparatus and a distance corresponding to the C/A code length; and

determining the pseudo range based on the delay time obtained as a result of the first step and the range determined as a result of the second step.

3. The method of claim 1, wherein the external apparatus is located within a range from the GPS terminal in which a signal will propagate during transmission of one half of the C/A code.

2. A GPS terminal removed from an external apparatus of which a pseudo range between a satellite and the GPS terminal is determined, comprising:

a delay time calculation unit for determining a delay time by correlation calculation using a C/A code of a GPS signal received from the satellite;

a pseudo range calculation unit determining the pseudo range, based on a range in which the pseudo range is included, the range being determined based on a distance between the satellite and the external apparatus and a distance corresponding to the C/A code length, the pseudo range also being determined based on the delay time calculated by said delay time calculation unit.

4. The GPS terminal of claim 2, wherein the external apparatus is located within a range from the GPS terminal in which a signal will propagate during transmission of one half of the C/A code.