Landmass fly-around boundary generation

• US 6,314,349 B1
• Filed: 12/21/1998
• Issued: 11/06/2001
• Est. Priority Date: 12/21/1998
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Roy, Jeffrey, Benevides, Karen, Tomasi, Steven W.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US09/226,632
• Time in Patent Office: 1,051 Days
• Field of Search: 701/1, 701/3, 701/23, 701/25, 701/26, 701/200, 701/201, 701/202, 701/205, 701/208, 701/209, 701/300, 244/3.1, 340/990, 340/995, 731/78.R, 702/5
• US Class Current: 701/23
• CPC Class Codes: F41G 7/34 based on predetermined target position data
• 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

A process for generating fly-around boundaries for use by projectiles such as missiles or the like which facilitates the steps of providing original cartographic data representative of at least one geographical position on a landmass and providing a predetermined value for the spacing of a fly-around boundary from the geographical position; digitizing the original data and creating a landmass model in a format which includes latitudinal and longitudinal coordinates of the geographical position; inputting the digitized data and the predetermined value into a data analyzer; generating new data representative of the fly-around boundary using the data analyzer based on the predetermined value and the land mass model, preferably by offsetting fly-around segments from the landmass model a distance equal to the predetermined value; and providing a navigational control for receiving the new data and using the new data for controlling the flight path of the missile along the boundary.

Claims

1. A process for determining a fly-around boundary for use by projectiles as a flight path, comprising the steps of:

providing original cartographic data representative of at least one geographical position on a landmass and providing a predetermined value for the spacing of a fly-around boundary from said geographical position;

digitizing said original data in a format which includes latitudinal and longitudinal coordinates of said at least one geographical position;

providing a means for analyzing said digitized data;

inputting said digitized data and said predetermined value into said means for analyzing; and

generating a fly-around boundary in digitized form from said predetermined value and said digitized data using said analyzing means.

2. The process according to claim 1 further comprising the steps of:

providing a navigational control means for steering the projectile; and

inputting said generated fly-around boundary into said navigational control means.

3. The process according to claim 2 further comprising the step of removing a portion of said digitized data for simplifying a landmass model being generated from said digitized data.

4. The process according to claim 2 wherein said coordinates are in the form of at least a first set of three successive digitized points, said first set including a starting endpoint, a finishing endpoint and an intermediate point arranged in a directional configuration, said step of removing comprising the steps of:

categorizing said directional configuration represented by said first set as being a convex or concave configuration;

measuring the direct distance between said starting and said finishing endpoint of said first set if said first set has said concave configuration;

updating said digitized data representative of said landmass model if said first set has said concave configuration by eliminating said intermediate point of said first set from said first set when said direct distance is less than said predetermined value and retaining the remainder of said points of said first set; and

reconfiguring said landmass model by connecting all remaining points of said first set by a segment and thereby creating a resultant landmass model.

5. The process according to claim 4 wherein said coordinates further include an entry point and an exit point and a second set of successive digitized points, the process comprising the steps of:

analyzing said first and second sets of said three digitized points sequentially beginning with said entry point;

designating said finishing endpoint of said first set as a starting endpoint for said second set if said intermediate point is eliminated;

designating said intermediate point of said first set as a starting endpoint for said second set if said intermediate point of said first set is not eliminated; and

repeating said steps of categorizing, measuring, updating and reconfiguring for said second set.

6. The process according to claim 5 wherein the process further comprises the steps of:

analyzing said resultant landmass model after the step of reconfiguring to locate any of said segments which cross over other segments at a point of intersection other than at an endpoint;

creating a new point at said point of intersection and adding said new point to said resultant landmass model; and

eliminating any portions of said segments extending toward said landmass and projecting from said point of intersection and eliminating any segments connected with said portions, so that a near filtered landmass model is created comprising near filtered segments and points.

7. The process according to claim 6 wherein the process further comprises the steps of:

repeating the steps of inputting, categorizing, measuring, updating and reconfiguring for said near filtered points and said near filtered segments of said near filtered landmass model and creating a filtered landmass model having filtered segments and points.

8. The process according to claim 1 wherein said digitized data is a single point representative of said landmass, and wherein said step of generating further comprising the step of:

generating connected sides of a polygon around said single point, wherein a centerpoint of each of said sides is offset a distance equal to said predetermined value and said single point is at the center of said multi-sided figure, said sides representing original fly-around segments.

9. The process according to claim 1 wherein said landmass model includes two distinct endpoints connected by at least one line segment representative of said landmass, and wherein said step of generating further comprising the steps of:

generating connected sides of a multi-sided figure around each of said endpoints, wherein a center point of each of said sides is offset at a distance equal to said predetermined value and each of said endpoints is the center of one of said multi-sided figures, said sides representing original fly-around segments;

connecting said multi-sided figures with additional fly-around segments extending between said multi-sided figures on each side of said at least one line segment; and

eliminating any points, connected sides or portions thereof located between said additional fly-around segments.

10. The process according to claim 7 wherein the filtered landmass model includes a landmass side and a water side, and wherein said step of generating further comprising the step of:

offsetting original fly-around segments from said filtered segments a distance equal to said predetermined value at an orientation substantially parallel to said filtered segments and toward said water side for setting said fly-around boundary.

11. The process according to claim 10 wherein said step of offsetting includes the steps of:

performing said step of offsetting in a sequential manner for at least first and second filtered segment sets each having two filtered segments, wherein said first filtered segment set includes a starting segment and a finishing segment and said finishing segment of said first filtered segment set becomes a starting segment for said second filtered segment set; and

identifying if either or both of said first and second filtered segment sets form a convex configuration.

12. The process according to claim 11 further including the step of:

adjusting said fly-around boundary by correcting an offsetting error for either or both of said first and second filtered segment sets if either or both of said first and second filtered segment sets is identified as having said convex configuration.

13. The process according to claim 12 wherein a filtered segment set having said convex configuration has a vertex defined by one of said filtered points, and wherein said original fly-around segments offset from said filtered segments of said filtered segment set include an initial fly-around vertex offset from said landmass vertex a distance greater than the predetermined value, said process further including:

said step of adjusting comprising generating a new fly-around segment offset from said landmass a distance equal to said predetermined value and substantially perpendicular to a line extending between said landmass vertex and said initial fly-around vertex such that said new fly-around segment intersects with said original fly-around segments and an extra portion of each of said original fly-around segments offset from said filtered segment set having said convex configuration extends beyond said new fly-around segment toward said initial fly-around vertex; and

eliminating each extra portion and any points associated with each said extra portion and forming a new fly-around boundary.

14. The process according to claim 11 further comprising the step of:

correcting an additional error associated with performing the step of offsetting for said first and second filtered segment sets when said first and second filtered segment sets form consecutively arranged convex and concave configurations.

15. The process according to claim 14 wherein said additional error occurs when at least one of said original fly-around segments is offset from one of said filtered segments of said first filtered segment set at said predetermined value and said at least one of said original fly-around segments of said first filtered segment set violates a required offset at said predetermined value from a filtered segment of said second filtered segment set, and wherein said additional error correcting step comprises:

determining a point of intersection between original fly-around segments offset from said filtered segment of each of said first and second filtered segment sets, wherein at least one of said original fly-around segments of said first filtered segment set includes a portion which violates said required predetermined value offset from said filtered segment of said second filtered segment set; and

eliminating said portion of said first filtered segment set which violates said required predetermined value offset of said second filtered segment set.

16. The process according to claim 10 wherein said landmass represented by said digitized data is in the form of a portion of a non-island landmass and said fly-around boundary includes an entry original fly-around segment and exit original fly-around segment coinciding with exit and entry points of said filtered landmass model, said process further comprising the step of:

extending each of said entry and exit original fly-around segments by an amount equal to said predetermined value.

17. The process according to claim 13 wherein said cartographic data is provided for a plurality of landmasses, said process further comprising the steps of:

determining fly-around boundaries for each of said plurality of landmasses; and

combining the fly-around boundaries of at least two of said plurality of landmasses and creating a resultant fly-around boundary.

18. The process according to claim 17 wherein said step of combining the fly around boundaries further includes the steps of:

designating a fly-around boundary of one of said plurality of landmasses a base landmass boundary and designating a fly-around boundary of at least one of said plurality of landmasses a remaining landmass boundary;

determining points of intersection between said base landmass boundary and said remaining landmass boundary, wherein said points of intersection trap at least one of an inner fly-around point, an original fly-around segment and a portion of said original fly-around segment therebetween belonging to said base landmass boundary and said remaining landmass boundary; and

eliminating at least one of said inner fly-around point, said original fly-around segment, and said portion of said original fly-around segment for completing said resultant fly-around boundary.

19. The process according to claim 18 wherein said step of combining the fly-around boundaries further comprises the steps of:

redesignating said resultant fly-around boundary as a new base landmass boundary; and

repeating said steps of determining points of intersection and eliminating for said new base landmass boundary and any of said remaining landmass boundaries.

20. The process according to claim 18 further comprising the steps of:

redesignating a non-intersecting one of said remaining landmass boundaries a new base landmass boundary if no intersection between the base landmass boundary and said remaining landmass boundary is found; and

repeating said steps of determining points of intersection and eliminating for said new base landmass boundary and any remaining landmass boundaries.