초록 ▼

A method for automatically generating a point-reduced backtrack route is provided, using the aid of Global Positioning System technology. The method begins by recording a potentially very large series of data points using GPS technology and a user-selected point recording algorithm into a forward-tr

A method for automatically generating a point-reduced backtrack route is provided, using the aid of Global Positioning System technology. The method begins by recording a potentially very large series of data points using GPS technology and a user-selected point recording algorithm into a forward-track route. A point-reducing algorithm is then used to reduce the forward track to a backtrack route which preserves the topological essence of the original route, but with far fewer data points. This reduced backtrack route is then suitable for storage in a memory constrained device, and is suitable for backtrack navigation without the need for the large set of original route points. Storage of a number of such backtrack routes is thus made available to the end user.

대표청구항 ▼

1. A method for generating a backtrack from a plurality of data points which have been stored in a memory of a Global Positioning System, said data points having a first, last and intermediate data points corresponding to geographic positions, the method comprising the steps of:initializing a counte

1. A method for generating a backtrack from a plurality of data points which have been stored in a memory of a Global Positioning System, said data points having a first, last and intermediate data points corresponding to geographic positions, the method comprising the steps of:initializing a counter C to a value of 1, said counter C corresponding to a memory location on a memory stack; storing said last data point in said memory stack at a first memory location; assigning said last data point to a variable E; initializing a stack counter N to a value of 2; assigning said first data point to a variable B; comparing said counter C to zero; conducting the following steps if said counter C is greater than zero: computing a straight line from said variable B to said variable E; computing a shortest distance for each of said intermediate data points from said straight line, thereby having a plurality of shortest distances corresponding in a one to one relationship to said intermediate data points; determining the longest of each of said shortest distances and assigning said intermediate data point corresponding to said longest distance to a variable L and assigning said longest distance to a variable D; comparing said variable D to a threshold value; increasing the value of counter N by one, storing said variable L in said memory stack at memory location S(C), assigning the value of variable L to variable E, and returning to said comparing said counter C to zero step; if D is greater than said threshold value; decreasing the value of counter C by one, assigning the value of variable E to variable B and assigning the value of stack memory location S(c-1) to variable E, and returning to said comparing said counter C to zero step; if D is less than or equal to said threshold value; conducting the following steps if variable C is less than or equal to zero; comparing N to a predetermined memory limit; increasing said threshold value by a predetermined value, and returning to initializing a counter C step; if N is greater than said memory limit; and navigating to said first position utilizing said positions stored in said stack as way-points for said global positioning system.