POSITION MEASURING DEVICE AND POSITION MEASURING METHOD BY MEANS OF GPS

• US 20110205109A1
• Filed: 07/30/2009
• Published: 08/25/2011
• Est. Priority Date: 09/25/2008
• Status: Active Grant

• Current Assignee: Hitachi Zosen Corporation
• Original Assignee: Hitachi Zosen Corporation
• Inventors: Yoshida, Haruhiko, Miyake, Toshihide, Abe, Tomohiro
• Granted Patent: US 8,604,972 B2
• Time in Patent Office: Days
• US Class Current: 342/357.29
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry
• CPC Class Codes: G01S 19/44 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method

Abstract

In a position measuring method, GPS ranging data obtained at a reference station 1 and an observation station 2 is inputted to four solution calculating sections 12, RTK solutions such as a fix solution at the observation station 2 are calculated in the solution calculating sections 12 according to the RTK system, and the RTK solutions are inputted to a solution obtaining unit 13. Further, it is decided whether or not the RTK solutions include multiple fix solutions. When it is decided that the RTK solutions include multiple fix solutions, deviations between the fix solutions are determined and it is decided whether or not the deviations exceed an allowable value. When it is decided that none of the deviations exceed the allowable value, predetermined arithmetic processing is performed on the fix solutions to obtain a normal fix solution. Moreover, the solution calculating sections are sequentially restarted at predetermined time intervals.

Claims

1. A position measuring device by means of GPS, the device measuring a three-dimensional position of a moving object based on GPS ranging data obtained at a reference station that is a reference GPS receiver installed on ground and GPS ranging data obtained at an observation station that is an observation GPS receiver disposed on the moving object to be located,

the position measuring device comprising multiple solution calculating sections that receive the GPS ranging data from the reference station and the GPS ranging data from the observation station and are capable of calculating RTK solutions such as a fix solution and a float solution as position data of the observation station according to a real time kinematic (RTK) system, the solution calculating sections being sequentially restarted at predetermined time intervals,

the position measuring device further comprising a solution obtaining unit for receiving the RTK solutions outputted from the solution calculating sections and obtaining a normal fix solution;

the solution obtaining unit comprising;

a number decision section for deciding whether or not the inputted RTK solutions include multiple fix solutions;

a deviation calculating section for determining, when the number decision section decides that the RTK solutions include multiple fix solutions, deviations between the fix solutions; and

an allowable value decision section for deciding whether or not the deviations calculated by the deviation calculating section exceed an allowable value,

wherein when the allowable value decision section decides that none of the deviations exceed the allowable value, a normal fix solution is obtained based on the fix solutions.

2. The position measuring device by means of GPS according to claim 1, wherein the observation station is installed on an observation buoy moored in a predetermined sea area and the position data is calculated as a sea-level position.

3. A position measuring method by means of GPS, comprising:

inputting, to multiple solution calculating sections, GPS ranging data obtained at a reference station that is a reference GPS receiver installed on ground and GPS ranging data obtained at an observation station that is an observation GPS receiver disposed on a moving object to be located;

calculating RTK solutions such as a fix solution and a float solution as position data of the observation station according to a real time kinematic (RTK) system in the respective solution calculating sections;

deciding whether or not the obtained RTK solutions include multiple fix solutions;

determining, when it is decided that the RTK solutions include multiple fix solutions, deviations between the fix solutions;

deciding whether or not the determined deviations exceed an allowable value; and

obtaining a normal fix solution based on the fix solutions when it is decided that none of the deviations exceed the allowable value,

wherein the solution calculating sections are sequentially restarted at predetermined time intervals.

4. The position measuring method by means of GPS according to claim 3, wherein the observation station is installed on an observation buoy moored in a predetermined sea area and the position data is calculated as a sea-level position.