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Grid Scan
7.1.4
Starting data collection
Press Start when all the parameters are setup and data collection is ready to begin.
7.2 Laying out the grid
Positional accuracy of each line is vital to locating targets of interest once data has been
processed. Follow the steps below to layout the grid.
Step 1 – Define the axis- Lines parallel to the Y-Axis are called Y-Lines. Similarly, lines parallel
to the X-Axis are called X-Lines (Figure 7-5). Pick the origin of the grid such that it is the
furthest corner away from any obstacles. This way, all the lines start properly, but they can be
ended early if there is an obstruction.
Figure 7-5: X-Lines and Y-Lines relative to the Origin.
Step 2 – Layout the Grid – for maximum accuracy, it's very important to establish a right-angle
triangle (Figure 7-6). The easiest way is to use a single tape measure and refer to the diagram
below. Start at the origin, walk out the desired distance for x-axis (A) and mark that point. Then
then turn 90 degrees and walk out the desired distance for the y-axis (B) and mark that point.
Determine the hypotenuse side (C) from the screen (Figure 7-1), then close in the triangle (C -
hypotenuse side) back to the origin, making sure you meet the origin at the distance for C. If
not, move that last point in tandem with the origin, such that both sides of the tape measure are
taut.
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