Marine navigation device with improved contour lines

• US 9,423,258 B2
• Filed: 08/01/2014
• Issued: 08/23/2016
• Est. Priority Date: 08/02/2013
• Status: Active Grant

• Current Assignee: Garmin Switzerland GmbH (Garmin Limited)
• Original Assignee: Garmin Switzerland GmbH (Garmin Limited)
• Inventors: Kabel, Darrin W., Cowen, Michael A.
• Primary Examiner(s): Butler, Rodney
• Assistant Examiner(s): BRUSHABER, FREDERICK M
• Application Number:
  US14/449,688
• Publication Number:
  US 20150039222A1
• Time in Patent Office: 753 Days
• US Class Current: 1/1
• CPC Class Codes: G01C 21/203 Specially adapted for sailing ships

Abstract

A marine navigation device comprises a location determining element, a display, a memory element, and a processing element. The location determining element determines a current geolocation of a marine vessel on a first body of water. The display displays a map representation. The memory element stores digital elevation model data and sonar data for a plurality of bodies of water. The processing element is in communication with the memory element and is configured to select the digital elevation model data or the sonar data from the memory element corresponding to the first body of water, calculate contour line data, the contour line data determining a plurality of contour lines, update the contour line data by selectively removing at least a portion of the contour lines, and generate a map representation including contour lines derived from the updated contour line data, and control the display to visually present the map representation.

Claims

1. A marine navigation device comprising:

a location determining element configured to determine a current geolocation of a marine vessel on a first body of water;

a display;

a memory element configured to store digital elevation model data or sonar data for one or more bodies of water; and

a processing element in communication with the memory element and the display, the processing element configured to—

select the digital elevation model data or the sonar data from the memory element corresponding to the first body of water,

calculate contour line data using the digital elevation model data or the sonar data for at least a portion of the first body of water, the contour line data determining a plurality of contour lines, each contour line indicating all of the geolocations of underwater terrain that exist at a depth of water,

identify a high contour line density area having at least three adjacent contour lines within a threshold distance;

update the contour line data to reduce contour line density in the high contour line density area by selectively removing at least a portion of the at least three adjacent contour lines in the high contour line density area,

generate a map representation of at least a portion of the first body of water corresponding to the current geolocation, the map representation including contour lines derived from the updated contour line data, and

control the display to visually present the map representation.

2. The marine navigation device of claim 1, wherein the processing element identifies the high contour line density area by determining a line to line distance for adjacent contour lines and updates the contour line data by removing at least a portion of the contour lines in the high contour line density areas where the line to line distance is below a threshold value.

3. The marine navigation device of claim 2, wherein the line to line distance for adjacent contour lines is determined based on a zoom level of the map representation and a contour line depth range.

4. The marine navigation device of claim 3, wherein the zoom level is related to a size of an area of the first body of water that is displayed on the map representation.

5. The marine navigation device of claim 3, wherein the contour line depth range is determined by a value of the depth for which a contour line is displayed on the map representation.

6. The marine navigation device of claim 1, wherein the processing element identifies the high contour line density area by determining where a line to line distance for each adjacent pair of at least three adjacent contour lines is below the threshold value, and wherein the processing element is further configured to —

determine a window that surrounds the high contour line density area,

determine the two outermost contour lines in the window, and

remove segments of contour lines that lie within the window for the contour lines in between the two outermost contour lines.

7. The marine navigation device of claim 1, wherein the digital elevation model data includes a plurality of geolocations, each geolocation associated with an elevation value.

8. The marine navigation device of claim 1, wherein the sonar data includes a plurality of geolocations, each geolocation associated with a depth value.

9. The marine navigation device of claim 1, wherein the selective removal of at least a portion of the contour lines reduces the density of contour lines in the high contour line density area.

10. The marine navigation device of claim 1, wherein the processing element identifies the high contour line density area based on the number of contour lines in a geographic area.

11. The marine navigation device of claim 10, wherein the processing element counts the number of contour lines in the geographic area per unit length.

12. The marine navigation device of claim 10, wherein the processing element counts the number of contour lines in the geographic area per unit area of the display.

13. The marine navigation device of claim 1, wherein the processing element identifies that a geographic area associated with underwater terrain having a large gradient or slope is a high contour line density area.

14. A marine navigation device comprising:

a location determining element configured to determine a current geolocation of a marine vessel on a first body of water;

a display;

a memory element configured to store digital elevation model data or sonar data for one or more bodies of water; and

a processing element in communication with the memory element and the display, the processing element configured to—

select the digital elevation model data or the sonar data from the memory element corresponding to a first body of water,

calculate contour line data using the digital elevation model data or the sonar data for at least a portion of the first body of water, the contour line data determining a plurality of contour lines, each contour line indicating all of the geolocations of underwater terrain that exist at a depth of water,

determine a line to line distance for adjacent contour lines,

update the contour line data to reduce contour line density by removing at least a portion of at least one of the adjacent contour lines in high contour line density areas where the line to line distance is below a threshold value,

generate a map representation of at least a portion of the first body of water corresponding to the current geolocation, the map representation including contour lines derived from the updated contour line data, and

control the display to visually present the map representation.

15. The marine navigation device of claim 14, wherein the processing element is further configured to—

determine a high contour line density area where a line to line distance for each adjacent pair of at least three adjacent contour lines is below the threshold value,

determine a window that surrounds the high contour line density area,

determine the two outermost contour lines in the window, and

remove segments of contour lines that lie within the window for the contour lines in between the two outermost contour lines.

16. The marine navigation device of claim 14, wherein the line to line distance for adjacent contour lines is determined based on a zoom level of the map representation and a contour line depth range.

17. The marine navigation device of claim 16, wherein the zoom level is related to a size of an area of the first body of water that is displayed on the map representation.

18. The marine navigation device of claim 16, wherein the contour line depth range is determined by a value of the depth for which a contour line is displayed on the map representation.

19. The marine navigation device of claim 14, wherein the digital elevation model data includes a plurality of geolocations, each geolocation associated with an elevation value.

20. The marine navigation device of claim 14, wherein the sonar data includes a plurality of geolocations, each geolocation associated with a depth value.

21. The marine navigation device of claim 14, wherein the removal of at least a portion of at least one of the adjacent contour lines reduces the density of contour lines in the high contour line density area.

22. The marine navigation device of claim 14, wherein the high contour line density areas include a plurality of contour lines in a geographic area.

23. The marine navigation device of claim 22, wherein the processing element counts the number of contour lines in the geographic area per unit length.

24. The marine navigation device of claim 22, wherein the processing element counts the number of contour lines in the geographic area per unit area of the display.

25. The marine navigation device of claim 14, wherein the processing element identifies a geographic area associated with underwater terrain having a large gradient or slope as a high contour line density area where the line to line distance is below a threshold value.

26. A marine navigation device comprising:

a location determining element configured to determine a current geolocation of a marine vessel on a first body of water;

a display;

a memory element configured to store digital elevation model data or sonar data for one or more bodies of water; and

a processing element in communication with the memory element and the display, the processing element configured to—

select the digital elevation model data or the sonar data from the memory element corresponding to the first body of water,

calculate contour line data using the digital elevation model data or the sonar data for at least a portion of the first body of water, the contour line data determining a plurality of contour lines, each contour line indicating all of the geolocations of underwater terrain that exist at the depth of water,

determine a line to line distance for adjacent contour lines,

determine an area where the line to line distance for each adjacent pair of at least three adjacent contour lines is below the threshold value,

determine a window that surrounds the area,

determine the two outermost contour lines in the window,

update the contour line data by removing segments of contour lines that lie within the window for the contour lines in between the two outermost contour lines,

generate a map representation of at least a portion of the first body of water corresponding to the current geolocation, the map representation including contour lines derived from the updated contour line data, and

control the display to visually present the map representation.

27. The marine navigation device of claim 26, wherein the line to line distance for adjacent contour lines is determined based on a zoom level of the map representation and a contour line depth range.

28. The marine navigation device of claim 27, wherein the zoom level is related to a size of an area of the first body of water that is displayed on the map representation.

29. The marine navigation device of claim 27, wherein the contour line depth range is determined by a value of the depth for which a contour line is displayed on the map representation.

30. The marine navigation device of claim 26, wherein the digital elevation model data includes a plurality of geolocations, each geolocation associated with an elevation value and the sonar data includes a plurality of geolocations, each geolocation associated with a depth value.

31. The marine navigation device of claim 26, wherein the removal of a segment of at least one of the adjacent contour lines that lie within the window reduces the density of contour lines in the area.

32. The marine navigation device of claim 26, wherein the processing element determines the area based on the number of contour lines in a geographic area.

33. The marine navigation device of claim 32, wherein the processing element counts the number of contour lines in the geographic area per unit length.

34. The marine navigation device of claim 32, wherein the processing element counts the number of contour lines in the geographic area per unit area of the display.

35. The marine navigation device of claim 26, wherein the processing element determines that a geographic area associated with underwater terrain having a large gradient or slope is an area where the line to line distance for each adjacent pair of at least three adjacent contour lines is below the threshold value.