Download LTPP Manual for Profile Measurements and Processing

Figure 127. Placement of vertical photocell target in relation to section starting location.
The following procedure should be followed for collecting data:
1. In the Header Screen (see figure 84) set the Stop Method to DISTANCE and enter a value of
20 in the Distance field.
2. Set the vertical photocell to be active by checking the Auto Trigger under ODS 3 (see figure
84). Auto Trigger under ODS2 should not be checked. Collect three profile runs at the
section using standard LTPP data collection procedures. Data collection for these runs is
initiated by the vertical photocell.
3. Set the horizontal photocell to be active by checking the Auto Trigger under ODS 2 (see
figure 84). Auto Trigger under ODS3 should not be checked. Collect three profile runs at the
section using standard LTPP data collection procedures. Data collection for these runs is
initiated by the vertical horizontal photocell.
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