Scanning charts with StarNavPilot

Step 1: the shooting..

Place the chart on the floor in a well lit room. Hold the camera straight and vertical to the center at a height to fit the useful part of the map. Sometimes it is better to remove a little camera and zoom as a wide angle lens may provide more distortion.

Step 2: load the chart into StarNavPilot.

Load the picture into your computer and open it with the command 'Load a scan or a raster chart'.

Step 3: Fix a possible inclination of the shooting.

Despite all the attention that you could bring to the shooting, it is likely that the chart looks a little. The first thing to do is to correct the tilt which takes 2 clicks on a horizontal line with the corresponding function of StarNavPilot.

Step 4: The georeferencing.

Georeferencing is to provide the coordinates of at least 2 points on the chart and as far as possible vertically and horizontally. You will then choose a point in the upper left corner of the chart (NO) and a point in the bottom right corner (SE) of the chart. On a nautical chart the simplest way is to use the crossing of parallels and meridians, but you can also choose points on the graduated edges of the chart.

Verification of the chart:

At this stage the chart is georeferenced and if the shooting was done with a good camera, it can be used as this. Check by moving the cursor on the surface of the charts if the positions of parallels and meridians are accurate over the entire surface of the chart. If you notice any discrepancies you have to apply some corrections to this charts. This is usually the case because of the optical defects of common lens or a slight tilt at the shooting.

Step 5: Apply corrections georeferencing.

On a nautical chart it is very easy to apply a correction grid. Just create a correction point at each intersection of parallels and meridians. These corrections are very easy to enter because it needs simply to round the coordinates of the points. For example, if you read W004 ° 10'06"and N47 ° 19'48" at the intersection of meridian 4 ° 10 'and paralell 47 ° 20 you just need to round the coordinates of this point to W004 ° 10' and N47 ° 20 '.

The chart is ready:

This chart is now operational. After further check by moving the cursor on the surface of the chart that the positions of parallels and meridians are accurate over the entire surface of the chart, lock the georeferencing of the chart to prevent accidental changes. You can say that you scanned your chart and that it has become an ENC (Electronic Nautical Chart).

IMPORTANT: Back up your digital charts.

StarNavPilot has an export charts function. You can export all or parts of your charts to mobile supports or even CD ROMs or DVD. A StarNavPilot charts CDRom or DVD has at its root an autonomous installation utility allowing to select the charts to reinstall. In case of problem, you can then reinstall your charts on your computer or even on another computer if you use multiple computers on your boat or if you have created your CDrom or DVD with another computer than the one of your boat.

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