Carrier phase-based relative positioning apparatus

• US 6,611,228 B2
• Filed: 07/24/2001
• Issued: 08/26/2003
• Est. Priority Date: 07/24/2000
• Status: Active Grant

• Current Assignee: Furuno Electric Co, Ltd
• Original Assignee: Furuno Electric Co, Ltd
• Inventors: Nakayama, Kaoru, Toda, Hiroyuki, Sato, Sadao, Fukuda, Masaru
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US09/910,850
• Publication Number:
  US 20020050943A1
• Time in Patent Office: 763 Days
• Field of Search: 342/357.04, 701/215
• US Class Current: 342/357.38
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/55 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method

Abstract

A carrier phase-based relative positioning apparatus comprises a plurality of antennas of which at least one is installed on a mobile unit. The apparatus determines the position of each antenna other than one antenna used as a reference antenna relative to the reference antenna by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single difference phase or a double difference phase, and calculating an integer ambiguity of the single difference phase or the double difference phase. The apparatus judges that the integer ambiguity has been incorrectly determined if the position of any of the antennas relative to the reference antenna (or the angle of a flat plane formed by those two antennas) falls out of a preset range in which the relative position (the angle of the flat plane) falls under normal conditions.

Claims

1. A carrier phase-based relative positioning apparatus comprising:

a plurality of antennas of which at least one is installed on a mobile unit;

means for determining the relative positions of the multiple antennas by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single phase difference or a double phase difference, and calculating an integer ambiguity of the single phase difference or the double phase difference; and

means for judging whether the integer ambiguity has been correctly determined based on whether the relative positions of the antennas fall in a preset range in which the relative positions will fall under normal conditions.

6. A carrier phase-based relative positioning apparatus as claimed in claims 1, 2, 3, 4 or 5 in which a plurality of antennas are installed on a mobile unit.

2. A carrier phase-based relative positioning apparatus comprising:

a plurality of antennas of which at least one is installed on a mobile unit;

means for determining the attitude of a baseline vector between at least two of the multiple antennas by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single difference phase or a double difference phase, and calculating an integer ambiguity of the single difference phase or the double difference phase; and

means for judging whether the integer ambiguity has been correctly determined based on whether the attitude falls in a preset range in which the attitude will fall under normal conditions.

3. A carrier phase-based relative positioning apparatus comprising:

a plurality of antennas of which at least one is installed on a mobile unit;

means for determining the attitude of the mobile unit from the relative positions of two of the multiple antennas by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single difference phase or a double difference phase, and calculating an integer ambiguity of the single difference phase or the double difference phase; and

means for judging whether the integer ambiguity has been correctly determined by comparing said attitude with the attitude of the mobile unit measured by an attitude measuring device without using the radio signals from the position-fixing satellites and judging whether the difference between said two attitudes fall in a preset range in which the difference between both will fall under normal conditions.

4. A carrier phase-based relative positioning apparatus comprising:

a plurality of antennas of which at least one is installed on a mobile unit;

means for obtaining at least two baseline vectors from two pairs of the multiple antennas by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single phase difference or a double phase difference, and calculating an integer ambiguity of the single phase difference or the double phase difference; and

means for judging whether the integer ambiguity has been correctly determined by calculating the cross product of the two baseline vectors and judging whether the cross product falls in a preset range in which the cross product will fall under normal conditions.

5. A carrier phase-based relative positioning apparatus comprising:

a plurality of antennas of which at least one is installed on a mobile unit;

means for obtaining at least two baseline vectors from two pairs of the multiple antennas by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single phase difference or a double phase difference, and calculating an integer ambiguity of the single phase difference or the double phase difference;

means for calculating the cross product of the two baseline vectors;

means for determining the attitude of the baseline vectors; and

means for judging whether the integer ambiguity has been correctly determined based on whether the attitude of the baseline vectors and the cross product fall in preset ranges in which they will fall under normal conditions.

7. A carrier phase-based relative positioning apparatus comprising:

a plurality of antennas installed on a body or on a moving body;

means for determining the relative positions of the multiple antennas by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single phase difference or a double phase difference, and calculating an integer ambiguity of the single phase difference or the double phase difference; and

means for judging whether the integer ambiguity has been correctly determined based on whether a parameter based on the relative positions of the antennas falls in a preset range in which the parameter will fall under normal conditions.

8. A carrier phase-based relative positioning apparatus as claimed in claim 7 in which a parameter is the attitude of a baseline vector or vectors between at least two of the multiple antennas determined.

9. A carrier phase-based relative positioning apparatus comprising:

three antennas installed on a body or on a moving body;

means for determining the relative positions of said three antennas by receiving radio signals transmitted from a plurality of position-fixing satellites with said three antennas, observing a single phase difference or a double phase difference, and calculating an integer ambiguity of the single phase difference or the double phase difference; and

means for judging whether the integer ambiguity has been correctly determined based on whether a parameter based on the relative positions of the antennas falls in a preset range in which the parameter will fall under normal conditions.

10. A carrier phase-based relative positioning apparatus comprising:

two antennas installed on a mobile unit;

means for determining the relative positions of said two antennas by receiving radio signals transmitted from a plurality of position-fixing satellites with said two antennas, observing a single difference phase or a double difference phase, and calculating an integer ambiguity of the single difference phase or the double difference phase; and

means for judging whether the integer ambiguity has been correctly determined based on whether a parameter based on the relative positions of the antennas falls in a preset range in which the parameter will fall under normal conditions.