PSEUDORANGE CALCULATION METHOD, POSITION CALCULATION METHOD, COMPUTER-READABLE RECORDING MEDIUM, AND POSITION CALCULATION DEVICE

• US 20090262019A1
• Filed: 04/02/2009
• Published: 10/22/2009
• Est. Priority Date: 04/22/2008
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Gobara, Naoki
• Granted Patent: US 7,940,209 B2
• Time in Patent Office: Days
• US Class Current: 342/357.460
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain

Abstract

A pseudorange calculation method for calculating a pseudorange in a position calculation device includes: passing a received signal received from a satellite for position calculation through a first filter; passing the received signal through a second filter having a different phase characteristic from that of the first filter; calculating a first pseudorange on the basis of a signal acquired by passing through the first filter; calculating a second pseudorange on the basis of a signal acquired by passing through the second filter; and calculating a third pseudorange to be used for position calculation, on the basis of the first pseudorange and the second pseudorange.

Claims

1. A pseudorange calculation method for calculating a pseudorange in a position calculation device comprising:

passing a received signal received from a satellite for position calculation through a first filter;

passing the received signal through a second filter having a different phase characteristic from that of the first filter;

calculating a first pseudorange on the basis of a signal acquired by passing through the first filter;

calculating a second pseudorange on the basis of a signal acquired by passing through the second filter; and

calculating a third pseudorange to be used for position calculation, on the basis of the first pseudorange and the second pseudorange.

2. The pseudorange calculation method according to claim 1, wherein a pass band of the first filter includes a pass band of the second filter.

3. The pseudorange calculation method according to claim 1, wherein calculating the third pseudorange includes changing a weight of the first pseudorange and a weight of the second pseudorange on the basis of a difference between a pass band of the first filter and a pass band of the second filter, and carrying out weighted average operation of the first pseudorange and the second pseudorange.

4. The pseudorange calculation method according to claim 3, wherein calculating the third pseudorange includes changing the weight of the first pseudorange and the weight of the second pseudorange in such a manner that the weight of the first pseudorange becomes greater than the weight of the second pseudorange as the difference between the pass band of the first filter and the pass band of the second filter becomes greater.

5. The pseudorange calculation method according to claim 1, further comprising variably setting pass bands of the first filter and the second filter.

6. A position calculation method for carrying out position calculation using a pseudorange calculated by the pseudorange calculation method according to claim 1.

7. A position calculation device comprising:

a receiving unit which receives a position calculation signal from a satellite for position calculation;

a first filter which passes a signal having a first frequency band of the received signal;

a second filter which has a different phase characteristic from that of the first filter and passes a signal having a second frequency band of the received signal;

a calculation unit which calculates a third pseudorange on the basis of a first pseudorange calculated on the basis of a signal acquired by passing through the first filter and a second pseudorange calculated on the basis of a signal acquired by passing through the second filter; and

a position calculation unit which executes position calculation using the third pseudorange.