Apparatus for determining position location based on range differences

• US 3,881,096 A
• Filed: 09/19/1973
• Issued: 04/29/1975
• Est. Priority Date: 11/10/1971
• Status: Expired due to Term

• Current Assignee: Ralph O. Schmidt
• Original Assignee: Ralph O. Schmidt
• Inventors: Schmidt, Ralph O.
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US05/398,599
• Time in Patent Office: 587 Days
• Field of Search: 343/103,15,6.5,112R,112C,112TC 235/150.2,150.27,150.271,150.272
• US Class Current: 701/408
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G06G 7/78 for direction-finding, locating, distance or velocity measuring, or navigation systems

Abstract

Computing apparatus employing a range difference location-method wherein the reference stations are combined in fundamental triads to generate a straight line of position on which the location lies; the line of position being the axis of a general conic; each of the reference stations of the triad lying on the general conic; and the location being at a focus of said general conic.

Claims

1. Apparatus for determining the position of an unknown location, in response to signals defining the positions of at least three known locations and signals defining the different in distance between said unknown location and pairs of said known locations, comprising:

first computer means responsive to said signals defining positions and said signals defining distance differences for producing signals mathematically defining the axis of a conic bearing a relationship to said known locations, said axis passing through said unknown location; and

second computer means responsive to said signals mathematically defining the axis of a conic for producing signals specifying possible locations on said axis one of which is coincident with said unknown location.

2. Apparatus for determining the position of an unknown location as defined in claim 1 wherein said signals defining positions of known locations define positions of at least four unknown locations, and wherein said second computer means comprises:

third computer means responsive to said signals defining positions and said signals defining distance differences for producing signals mathematically defining the axis of a second conic, said axis passing through said unknown location; and

fourth computer means responsive to said signals defining said first and second conic axes for producing signals mathematically defining the intersection of said axes of said first and second conics, said intersection defining the position of said unknown location.

3. Apparatus as defined in claim 2 wherein said first computer means comprises a series of multiplier and adder circuits arranged to produce signals equivalent to the coefficients of an equation AX+BY C defining the axis of said conic and wherein said third computer means comprises a series of multiplier and adder circuits arranged to produce signals equivalent to the coefficients of an equation DX+EY F defining the axis of said second conic.

4. Apparatus as defined in claim 3 wherein said fourth computer means comprises a plurality of multiplication, subtraction and division circuits responsive to said signals equivalent to the coefficients of an equation AX+BY C and sais signals equivalent to the coefficients of an equation DX+EY F arranged to produce output signals equivalent to (CE-FB)/(AE-BD) and (AB-CD)/(AE-BD).