Radar navigation system

• US 4,893,127 A
• Filed: 04/03/1989
• Issued: 01/09/1990
• Est. Priority Date: 02/06/1987
• Status: Expired due to Fees

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Trommer, Jack R., Peters, Carsten H., Clark, Stanley L.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): CAIN, DAVID C
• Application Number:
  US07/333,890
• Time in Patent Office: 281 Days
• Field of Search: 342/386, 342/387, 342/388, 342/389, 342/407, 340/995, 364/444, 364/448, 364/449, 364/452, 364/456
• US Class Current: 342/386
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder

Abstract

A low cost electronic navigation system including a Loran receiver and a marine radar unit adapted to receive vessel position information from the Loran. A computer within the radar unit uses successive Loran outputs to display vessel heading and the bearing of objects of interest such as other vessels or waypoints in graphic and numeric form. The navigator may accurately determine the bearing of such objects of interest in magnetic or true form. Other modes are of particular use when the navigator is interested in using the system to maintain a desired course, to avoid obstacles, or to determine if and by how much he must change his present course to return to the desired course.

Claims

1. A method for displaying information used by a navigator in navigating a vessel, comprising the steps of:

obtaining from a Loran unit electronic representations of the vessel'"'"'s present position, the present course of the vessel, and the position of a waypoint;

generating a radar image including navigation obstructions in the area surrounding the vessel, the radar image also including a point corresponding to the vessel'"'"'s present position and a point substantially dead ahead of the vessel;

providing a display of the radar image together with a numeric representation of the present course, the numeric representation of the present course being displayed adjacent the point on the radar image dead ahead of the vessel;

overlaying a heading line on the display, the heading line having as endpoints the point corresponding to the vessel'"'"'s present position and the point substantially dead ahead of the vessel;

overlaying a graphic indication of the waypoint'"'"'s position on the display; and

overlaying a waypoint bearing line on the display, the waypoint bearing line having as endpoints the point corresponding to the vessel'"'"'s present position and a point adjacent the graphic indication of the waypoint'"'"'s position wherein the navigator is provided with the heading line, the bearing line to the waypoint, and navigation obstructions all on the display so that when the navigator deviates from the waypoint bearing to steer around navigation obstructions, there is a clear visual indication of that deviation by comparing the heading line with the waypoint bearing line.

2. An electronic apparatus for use by a navigator in navigating a vessel comprising:

means comprising a Loran receiver and computer for providing electronic representations of the present position of the vessel and the position of a waypoint selected by the navigator;

radar means for providing a radar image including navigation obstructions, the radar image having a certain range, the certain range including a point corresponding to the vessel'"'"'s present position, and a point dead ahead of the vessel;

means for providing a heading line image, the heading line image including a line having as endpoints a point corresponding to the vessel'"'"'s present position and a point corresponding to the point dead ahead of the vessel;

means, fed by said waypoint position, for providing a waypoint graphic image including an indicator positioned at a point corresponding to the position of the waypoint selected by the navigator;

means, controlled by the navigator, for providing an electronic bearing line image, the electronic bearing line image having endpoints at a point corresponding to the vessel'"'"'s present position and the point corresponding to the position of the waypoint selected by the navigator; and

display means for simultaneously displaying the radar image, the heading line image, the electronic bearing line image and the waypoint graphic image so that the navigator has a visual image on one display that includes the navigation obstructions, the heading line and the waypoint bearing line thereby enabling the navigator to compare the heading line with the waypoint bearing line while deviating course to steer around navigation obstructions.

3. A method for use by a navigator in navigating a vessel, comprising the steps of:

generating a radar image of the area surrounding the vessel including navigation obstructions, the radar image including a point corresponding to a present position of the vessel;

obtaining from a Loran unit an electronic representation of the position of the waypoint;

generating in response to the waypoint position electronic representation of a graphic waypoint image corresponding to the position of the waypoint;

overlaying the graphic waypoint image and the radar image;

overlaying a heading line on the radar image, the heading line having as endpoints the present position of the vessel and a point dead ahead of the vessel;

overlaying a waypoint bearing line on the radar image, the waypoint bearing line having as endpoints the point corresponding to the present position of the vessel and a point adjacent the graphic waypoint image; and

providing a visual display of said radar image including the navigation obstructions, the heading line and the waypoint bearing line wherein the heading line deviation from the waypoint bearing line can be viewed on the same display that includes navigation obstructions.

4. An electronic apparatus for use by a navigator in navigating a vessel comprising:

means comprising a Loran receiver and computer for providing an electronic representation of the waypoint relative to the present position of the vessel in response to an operator actuated input corresponding to the location of a waypoint;

radar means for providing a radar image having a certain range including a point corresponding to the vessel'"'"'s present position and a point dead ahead of the vessel, said radar image including navigation obstructions;

means for providing a heading line image including a line having as endpoints a point corresponding to the vessel'"'"'s present position and a point corresponding to the point dead ahead of the vessel;

means responsive to the waypoint electronic representation for providing a waypoint graphic image including an indicator positioned at a point corresponding to the position of the waypoint designated by the operator actuated input;

means for providing an electronic bearing line image having endpoints corresponding to the vessel'"'"'s present point and the point corresponding to the position of the waypoint designated by the operator actuated input; and

display means for simultaneously displaying the radar image including the navigation obstructions, the heading line image, the waypoint graphic image, and the waypoint electronic bearing line wherein the angle between the heading line and the waypoint bearing line provides on the display a graphic indication of how much and in what direction the vessel'"'"'s present course deviates from the course to the waypoint while at the same time having a visual presentation of the navigation obstructions on the same display.