State-of-the-art visual navigation aids include waypoint radar (FIGS. 7 and 8) and waypoint chart plotters (FIGS. 9 and 10). Waypoint radar systems generally comprise a radar combined with a compass, a position sensor, and a waypoint input. The location of the waypoint must be input in latitude and longitude (lat/long), or a derivative. Using this lat/long location, current position, and heading, waypoint radar systems calculate the range and relative bearing to the waypoint and display the waypoint on the radar sweep. The necessity of manually, numerically entering the waypoint location makes waypoint radar systems somewhat difficult and cumbersome to use, and introduces the possibility of user error in determining inputting the waypoint lat/long. Thus, for example, a user of waypoint radar may know where to steer to approach the waypoint but may not know whether the waypoint is his intended destination. Another disadvantage of this, and indeed of any radar based system, is the difficulty of discerning a target from clutter, and indeed from other targets.
Waypoint chart plotters generally comprise a chart plotter combined with a position sensor and a waypoint input. The waypoint can be selected from the chart display with a cursor or the like, and its location can be automatically read from the chart. The chart plotter calculates range and bearing to the waypoint from current position data and the waypoint location, and displays the waypoint at its location on the chart. Although a waypoint chart plotter helps a user visualize his position and course to the waypoint, it will not help him avoid a collision along his path to the waypoint.
USPTO Backgrounds
USPTO Backgrounds