Positioning apparatus, control method of positioning apparatus, control program for positioning apparatus, and computer readable recording medium for storing control program for positioning apparatus

• US 20070081581A1
• Filed: 10/06/2006
• Published: 04/12/2007
• Est. Priority Date: 10/11/2005
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Gobara, Naoki
• Application Number:
  US11/543,948
• Publication Number:
  US 20070081581A1
• Time in Patent Office: Days
• US Class Current: 375/150
• CPC Class Codes: G01S 19/22 Multipath-related issues

Abstract

A positioning apparatus for positioning based on satellite signals from positioning satellites includes: correlation information generating means for generating correlation information which indicates correlation values between the satellite signals and correlation purpose signals stored in the positioning apparatus; correlation information evaluating means for determining whether or not variation in the correlation values falls within a predetermined normal variation range; multipath determining means for determining whether or not the satellite signals are affected by a multipath based on determination results of the correlation information evaluating means; multipath correcting information generating means for generating multipath correcting information to correct effects of the multipath based on determination results of the multipath determining means and the correlation information; and correlation value correcting means for correcting the correlation values based on the multipath correcting information.

Claims

1. A positioning apparatus for positioning based on satellite signals from positioning satellites, comprising:

correlation information generating means for generating correlation information which indicates correlation values between the satellite signals and correlation purpose signals stored in the positioning apparatus;

correlation information evaluating means for determining whether or not variation in the correlation values falls within a predetermined normal variation range;

multipath determining means for determining whether or not the satellite signals are affected by a multipath based on determination results of the correlation information evaluating means;

multipath correcting information generating means for generating multipath correcting information to correct effects of the multipath based on determination results of the multipath determining means and the correlation information; and

correlation value correcting means for correcting the correlation values based on the multipath correcting information.

2. The positioning apparatus according to claim 1, wherein

the correlation values include code phase values and peak electric power values, and

the multipath determining means evaluates variation in the code phase values and that in the peak electric power values, respectively, and determines that the satellite signals are affected by a multipath when both of the code phase values and the peak electric power values do not fall within the normal variation range.

3. The positioning apparatus according to claim 1 or claim 2, comprising:

interference cycle determining means for determining an interference cycle in which the multipath interferes with the satellite signals, wherein

the multipath correcting information generating means generates the multipath correcting information based on the correlation information in the interference cycle.

4. A control method of a positioning apparatus, comprising the steps of:

generating correlation information which indicates correlation values between satellite signals and correlation purpose signals stored in a positioning apparatus by means of the positioning apparatus for positioning based on the satellite signals from positioning satellites;

evaluating correlation information for determining whether or not variation in the correlation values falls within a predetermined normal variation range by means of the positioning apparatus;

determining multipath for determining whether or not the satellite signals are affected by a multipath by means of the positioning apparatus based on determination results of the step of evaluating correlation information;

generating multipath correcting information to correct effects of the multipath by means of the positioning apparatus based on determination results of the multipath determining means and the correlation information; and

correcting correlation values for correcting the correlation values by means of the positioning apparatus based on the multipath correcting information.

5. A control program for a positioning apparatus, instructing a computer to perform the steps of:

generating correlation information which indicates correlation values between satellite signals and correlation purpose signals stored in a positioning apparatus by means of the positioning apparatus for positioning based on the satellite signals from positioning satellites;

evaluating correlation information for determining whether or not variation in the correlation values falls within a predetermined normal variation range by means of the positioning apparatus;

determining multipath for determining whether or not the satellite signals are affected by a multipath by means of the positioning apparatus based on determination results of the step of evaluating correlation information;

generating multipath correcting information to correct effects of the multipath by means of the positioning apparatus based on determination results of the multipath determining means and the correlation information; and

correcting correlation values for correcting the correlation values by means of the positioning apparatus based on the multipath correcting information.

6. A computer readable recording medium for storing a control program for a positioning apparatus, instructing a computer to perform the steps of:

generating correlation information which indicates correlation values between satellite signals and correlation purpose signals stored in a positioning apparatus by means of the positioning apparatus for positioning based on the satellite signals from positioning satellites;

evaluating correlation information for determining whether or not variation in the correlation values falls within a predetermined normal variation range by means of the positioning apparatus;

determining multipath for determining whether or not the satellite signals are affected by a multipath by means of the positioning apparatus based on determination results of the step of evaluating correlation information;

generating multipath correcting information to correct effects of the multipath by means of the positioning apparatus based on determination results of the multipath determining means and the correlation information; and

correcting correlation values for correcting the correlation values by means of the positioning apparatus based on the multipath correcting information.