DIGITAL MAP MATCHING

• US 3,879,728 A
• Filed: 03/13/1959
• Issued: 04/22/1975
• Est. Priority Date: 03/13/1959
• Status: Expired due to Term

• Current Assignee: Hanns H. Wolff
• Original Assignee: Hanns H. Wolff
• Inventors: Wolff, Hanns H.
• Primary Examiner(s): Hubler, Malcolm F.
• Application Number:
  US03/799,267
• Time in Patent Office: 5,884 Days
• Field of Search: 343/7,5,5MM,7ED 244/14,3.17 340/149,146.2,23,24,27
• US Class Current: 342/64
• CPC Class Codes: F41G 7/343 comparing observed and stored data of target position or of distinctive marks along the path towards the target
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence

Abstract

1. In a map matching system wherein a live map is compared with a reference map, the steps of dividing said maps into predetermined numbers of live and reference area elements, respectively, assigning numbers to said area elements so that the numerical difference between the numbers assigned to any two elements of a single map is the same as that between the numbers assigned to any other pair of elements of that map which have the same relative position to each other as said two elements, selecting the live elements that have a predetermined characteristic, comparing the number assigned to said selected live elements with the number assigned to predetermined reference elements which are known to have said characteristic, and determining when the numerical difference between the number assigned to one of said selected live elements and the number assigned to one of said predetermined reference elements is the same as the numerical difference between the number assigned to another of said live elements and the number assigned to another of said predetermined reference elements.

Claims

1. In a map matching system wherein a live map is compared with a reference map, the steps of dividing said maps into predetermined numbers of live and reference area elements, respectively, assigning numbers to said area elements so that the numerical difference between the numbers assigned to any two elements of a single map is the same as that between the numbers assigned to any other pair of elements of that map which have the same relative position to each other as said two elements, selecting the live elements that have a predetermined characteristic, comparing the number assigned to said selected live elements with the number assigned to predetermined reference elements which are known to have said characteristic, and determining when the numerical difference between the number assigned to one of said selected live elements and the number assigned to one of said predetermined reference elements is the same as the numerical difference between the number assigned to another of said live elements and the number assigned to another of said predetermined reference elements.

2. A map matching system according to claim 1, wherein said live map is formed by means of a reflected signal and including the step of selecting an intensity level of the reflected signals as said characteristic.

3. An automatic map matching system for comparing a live map of a given region with a reference map, said reference map being divided into a predetermined number of area elements having numbers assigned thereto, whereby the numerical difference between the numbers assigned to any two elements is the same as that between the numbers assigned to any other pair of elements which have the same relative position to each other as said two elements, comprising means for storing information relative to the numbers of those elements which have a predetermined characteristic, means for scanning a region and producing a live map thereof, said live map being subdivided into live area elements having numbers assigned thereto in the same manner as does said reference map, and computer means for determining the numerical difference between the numbers assigned to those live elements which have a predetermined characteristic and the numbers assigned to said stored reference elements.

4. A map matching system according to claim 3, including means for indicating when the numerical difference between the numbers assigned to two of said live elements having said predetermined characteristic and the numbers assigned to two of said stored reference elements, respectively, is the same.