Furuno GD-3300 Track Plotting Interval, How the track is drawn, Plot interval by time or distance

2.5 Track Plotting Interval

The plot interval determines how the track will be reconstructed on the display and track storage time. The equipment has two plot inter- vals, plot interval 1 and plot interval 2, which you can set as desired. You can select which one to use by the [PLOT INTVL] key. This section shows you how to preset the plot intervals, on the INITIAL SETTINGS menu.

How the track is drawn

The “quality” of the track displayed largely depends on the plot inter- val setting, smoothing rate, etc. In drawing the track, first the ship’s position fed from the navigation receiver is stored into this unit’s memory at an interval of time or distance selected by the operator. This interval of time or distance is called the “Plot Interval” and it is selected considering the ship’s speed, the chart scale, etc. If a shorter interval is selected, a reconstructed course line is provided with bet- ter accuracy, but total storage time of the track is reduced.

Plot interval and track reconstruction

Obviously there is a trade off between smooth reconstruction of the track and plot storage time: The shorter the interval the smoother the reconstruction but storage time is reduced. Figure 2-10 compares plot interval and track reconstruction.

ACTUALDISPLAYED

TRACKTRACK

Figure 2-10 Plot interval and track reconstruction

Plot interval by time or distance

The plot interval can be selected by “Time” (00 sec. to 99.59 min.) or “Distance” (00 nm to 9.99 nm). If the plot interval is selected by distance, you will not use up memory points when the boat is an- chored.

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