GPS CLOCKING DEVICE AND TIME DETECTION METHOD

• US 20100019968A1
• Filed: 07/22/2009
• Published: 01/28/2010
• Est. Priority Date: 07/25/2008
• Status: Abandoned Application

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Shingyoji, Ryuji
• Application Number:
  US12/507,155
• Publication Number:
  US 20100019968A1
• Time in Patent Office: Days
• US Class Current: 342/357.480
• CPC Class Codes: G01S 19/34 Power consumption

Abstract

According to one embodiment, a GPS clocking device comprises a computing module, a storage module, a reading module, and a correction module. The computing module receives a GPS signal transmitted from a GPS satellite, and computes a receiving position of the GPS signal in the standard coordinate system of the GPS based on the GPS signal. The storage module stores position information which indicates areas different from each other in the employed standard time, and is represented by the standard coordinate system, and information on the time difference between the standard time of each area and standard time of the GPS. The reading module reads time-difference information corresponding to an area to which the receiving position computed by the computing module corresponds from the storage module. The correction module corrects the current time indicated by the time information included in the GPS signal by using the time-difference information.

Claims

1. A GPS clocking device comprising:

a computing unit configured to receive a GPS signal transmitted from a GPS satellite and to compute a receiving position of the GPS signal in a standard coordinate system of a GPS based on the received GPS signal;

a storage configured to store position information which indicates areas of different standard times and is represented by the standard coordinate system and to store time difference information between the standard time of each area and a standard time of a GPS;

a reading unit configured to read, from the storage, time difference information corresponding to an area in which the receiving position computed by the computing unit is located; and

a correction unit configured to correct a current time indicated by time information included in the GPS signal by using the time difference information read by the reading unit.

2. The GPS clocking device according to claim 1, wherein

the computing unit is configured to compute the receiving position represented by the coordinate values (X, Y, Z) of the ECEF orthogonal coordinate system which is the standard coordinate system of the GPS based on a position of each satellite, and time necessary for a code for position measurement to reach the GPS clocking device by using Time Of Week information, ephemeris, satellite clock information, ionospheric correction data, and almanacs which are included in the GPS signal transmitted from a certain GPS satellite.

3. The GPS clocking device according to claim 1, wherein the standard time of the GPS comprises Coordinated Universal Time.

4. A time detection method comprising:

receiving a GPS signal transmitted from a GPS satellite;

computing a receiving position of the GPS signal in a standard coordinate system of a GPS based on the received GPS signal;

reading, from a storage configured to store position information which indicates areas of different standard times and is represented by the standard coordinate system, and to store time difference information between the standard time of each area and a standard time of the GPS, time difference information corresponding to an area in which the computed receiving position is located; and

correcting a current time indicated by time information included in the GPS signal by using the read time difference information.

5. The time detection method according to claim 4, wherein

the computing comprises computing the receiving position represented by the coordinate values (X, Y, Z) of the ECEF orthogonal coordinate system which is the standard coordinate system of the GPS based on a position of each satellite, and time necessary for a code for position measurement to reach the GPS clocking device by using Time Of Week information, ephemeris, satellite clock information, ionospheric correction data, and almanacs which are included in the GPS signal transmitted from a certain GPS satellite.

6. The time detection method according to claim 4, wherein the standard time of the GPS comprises Coordinated Universal Time.