Position-locating method and apparatus including corrections for elevational changes

Claim 1

A method of determining the instantaneous location of a land vehicle travelling on a terrain, comprising the following operations: measuring an approximate location of the land vehicle as said vehicle travels on the terrain by continuously measuring distances and headings of the land vehicle as said vehicle travels on the terrain from a known location, and determining the approximate location of said land vehicle by dead reckoning; measuring changes in elevation of the land vehicle as said vehicle travels on the terrain; continuously utilizing said measured changes in elevation for computing the horizontal component of said measured distances in order to determine the instantaneous location of the land vehicle on the terrain; storing reference data which includes changes in sign in the elevation slope of known locations on said terrain; and utilizing the changes in sign in the elevation slope of the reference data having known locations, and the changes in sign in the elevation slope of the measured data whose location was determined by dead reckoning, for periodically correcting the instantaneous location of the land vehicle on said terrain.

Claim 2

A method of determining the instantaneous location of a land vehicle travelling on a terrain, comprising the following operations: measuring an approximate location of the land vehicle as said vehicle travels on the terrain by continuously measuring distances and headings of the land vehicle as said vehicle travels on the terrain from a known location, and determining the approximate location of said land vehicle by dead reckoning; measuring changes in elevation of the land vehicle as said vehicle travels on the terrain; continuously utilizing said measured changes in elevation for computing the horizontal component of said measured distances in order to determine the instantaneous location of the land vehicle on the terrain; storing reference data which includes changes in sign in the elevation slope of known locations on said terrain; and utilizing the changes in sign in the elevation slope of the reference data having known locations, and the changes in sign in the elevation slope of the measured data whose location was determined by dead reckoning, for periodically correcting the instantaneous location of the land vehicle on said terrain.

Claim 5

A method of determining the location of a land vehicle travelling on a terrain, comprising the following operations: (a) measuring an approximate location of the land vehicle as said vehicle travels on the terrain; (b) measuring a parameter corresponding to the elevation of the land vehicle as said vehicle travels on the terrain; and (c) utilizing said measured elevation parameter of the land vehicle for correcting the measured approximate location of the vehicle to determine the instantaneous location of the land vehicle on said terrain; wherein: said operation (a) is performed by determining the approximate location of the land vehicle by means of a three-dimensional satellite global positioning system; said operation (b) measures changes in elevation of the land vehicle as said vehicle travels on the terrain; and said operation (c) is performed by (i) inputting and storing reference data which includes changes in sign in the elevation slope of known locations in said terrain; and (ii) utilizing the changes in sign in the elevation slope of the reference data and the known locations thereof, and the changes in sign in the elevation slope of the measured data whose approximate location was determined, for periodically correcting the instantaneous location of the land vehicle on said terrain.

Claim 6

A method of determining the location of a land vehicle travelling on a terrain, comprising the following operations: (a) measuring an approximate location of the land vehicle as said vehicle travels on the terrain; (b) measuring a parameter corresponding to the elevation of the land vehicle as said vehicle travels on the terrain; and (c) utilizing said measured elevation parameter of the land vehicle for correcting the measured approximate location of the vehicle to determine the instantaneous location of the land vehicle on said terrain; wherein: said operation (a) is performed by determining the approximate location of the land vehicle by means of a three-dimensional satellite global positioning system; said operation (b) measures changes in elevation of the land vehicle as said vehicle travels on the terrain; and said operation (c) is performed by (i) inputting and storing reference data which includes changes in sign in the elevation slope of known locations in said terrain; and (ii) utilizing the changes in sign in the elevation slope of the reference data and the known locations thereof, and the changes in sign in the elevation slope of the measured data whose approximate location was determined, for periodically correcting the instantaneous location of the land vehicle on said terrain.

Claim 13

A method of locating a vehicle travelling over a terrain, comprising the following: (a) measuring the approximate location of the vehicle as said vehicle travels over the terrain; (b) measuring a parameter corresponding to the elevation of the vehicle as said vehicle travels over the terrain; and (c) utilizing said measured parameter corresponding to the elevation of the vehicle for correcting the measured approximate location of the vehicle by: (i) storing, as reference data, known locations on said terrain wherein a change in sign in the elevation slope occurs; (ii) determining, from the measured parameter corresponding to the elevation of the vehicle, the locations where a change in sign occurs in the elevation slope of the terrain travelled by the land vehicle; (iii) and utilizing the occurrences of changes in sign in the elevation slope of the terrain travelled by the land vehicle for correcting the measured approximate location of the land vehicle by the respective known location stored in the reference data.

Claim 14

A method of locating a vehicle travelling over a terrain, comprising the following: (a) measuring the approximate location of the vehicle as said vehicle travels over the terrain; (b) measuring a parameter corresponding to the elevation of the vehicle as said vehicle travels over the terrain; and (c) utilizing said measured parameter corresponding to the elevation of the vehicle for correcting the measured approximate location of the vehicle by: (i) storing, as reference data, known locations on said terrain wherein a change in sign in the elevation slope occurs; (ii) determining, from the measured parameter corresponding to the elevation of the vehicle, the locations where a change in sign occurs in the elevation slope of the terrain travelled by the land vehicle; (iii) and utilizing the occurrences of changes in sign in the elevation slope of the terrain travelled by the land vehicle for correcting the measured approximate location of the land vehicle by the respective known location stored in the reference data.