Global positioning system

• US 5,210,540 A
• Filed: 06/12/1992
• Issued: 05/11/1993
• Est. Priority Date: 06/18/1991
• Status: Expired due to Term

• Current Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Original Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Inventors: Masumoto, Yutaka
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US07/897,710
• Time in Patent Office: 333 Days
• Field of Search: 342/357, 342/462, 364/449
• US Class Current: 342/357.28
• CPC Class Codes: G01C 5/06 by using barometric means
• CPC Class Codes: G01S 19/32 Multimode operation in a single same satellite system, e.g. GPS L1/L2
• CPC Class Codes: G01S 19/42 Determining position

Abstract

A global positioning system for positioning a mobile object such as an automobile in a global geometrical region includes a GPS receiver for receiving radio waves from a plurality of satellites and outputting either two-dimensional position data indicative of the present position of the mobile object in a two-dimensional position measurement mode or three-dimensional position data indicative of the present position of the mobile object in a three-dimensional position measurement mode. An altimeter detects a relative altitude of the mobile object and outputs relative altitude data indicative of the detected relative altitude. A present position output unit calculates present position data indicative of the present position of the mobile object solely based on the data from the GPS receiver while the GPS receiver is operating in the three-dimensional position measurement mode. When the GPS receiver operates in the two-dimensional position measurement mode, the present position output unit calculates present position data indicative of the present position of the mobile object based on the two-dimensional position data and the relative altitude data. The calculated present position data are sent to a display which displays the two-dimensional position of the mobile object and also the altitude data.

Claims

1. A global positioning system for positioning a mobile object in a global geometric region, comprising:

receiving means for receiving radio waves from a plurality of satellites and outputting one of (1) two-dimensional position indicative of the present position of the mobile object in a two-dimensional position measurement mode and (2) three-dimensional position data indicative of the present position of the mobile object in a three-dimensional position measurement mode, said two-dimensional position data comprising latitude and longitude data;

memory means for storing altitude data corresponding to said latitude and longitude data; and

calculating means for reading said altitude data from said memory means based on said latitude and longitude data and outputting present position data indicative of the present position of the mobile object when said receiving means outputs the two-dimensional position data in the two-dimensional position measurement mode.

2. A global positioning system according to claim 1, wherein said memory means is a CD-ROM.

3. A global positioning system for positioning a mobile object in a global geometrical region, comprising:

receiving means for receiving radio waves from a plurality of satellites and outputting one of (1) two-dimensional position data indicative of the present position of the mobile object in a two-dimensional position measurement mode and (2) three-dimensional position data indicative of the present position of the mobile object in a three-dimensional position measurement mode;

detecting means for detecting a relative altitude of the mobile object and outputting relative altitude data indicative of the detected relative altitude; and

calculating means for calculating and outputting present position data indicative of the present position of the mobile object based on said two-dimensional position data in said two-dimensional position measurement mode and said relative altitude data when said receiving means outputs the two-dimensional position data in the two-dimensional position measurement mode, said calculating means comprising means for calibrating said relative altitude data with altitude data of the three-dimensional position data previously output by said receiving means in said three-dimensional position measurement mode when said receiving means switches from said three-dimensional position measurement mode to said two-dimensional position measurement mode.

4. A global positioning system according to claim 3, wherein said detecting means is comprised of an air-pressure altimeter.

5. A global positioning system according to claim 3, wherein said calculating means includes mode detecting means for detecting whether said receiving means outputs the two-dimensional position data in the two-dimensional position measurement mode or the three-dimensional position data in the three-dimensional position measurement mode.

6. A global positioning system according to claim 5, wherein said detecting means is comprised of an air-pressure altimeter.

7. A global positioning system for positioning a mobile object in a global geometrical region, comprising:

receiving means for receiving radio waves from a plurality of satellites and outputting one of (1) two-dimensional position data indicative of the present position of the mobile object in a two-dimensional position measurement mode and (2) three-dimensional position data indicative of the present position of the mobile object in a three-dimensional position measurement mode;

detecting means for detecting a relative altitude of the mobile object and outputting relative altitude data indicative of the detected relative altitude; and

calculating means for calculating and outputting present position data indicative of the present position of the mobile object based on said two-dimensional position data in said two-dimensional position measurement mode and said relative altitude data when said receiving means outputs the two-dimensional position data in the two-dimensional position measurement mode, said calculating means comprising means for calibrating said relative altitude data with altitude data of the three-dimensional position data previously output by said receiving means in said three-dimensional position measurement mode, at all times with predetermined time intervals when said receiving means outputs the three-dimensional position data in said three-dimensional position data in said three-dimensional position measurement mode.

8. A global positioning system according to claim 7, wherein said detecting means is comprises of an air-pressure altimeter.

9. A global positioning system according to claim 7, wherein said calculating means includes mode detecting means for detecting whether said receiving means outputs the two-dimensional position data in the two-dimensional position measurement mode or the three-dimensional position data in the three-dimensional position measurement mode.

10. A global positioning system according to claim 9, wherein said detecting means is comprised of an air-pressure altimeter.