Download SCANNER surveys for Local Roads User Guide and Specification

Section 4 – Data Processing
If the X co-ordinate at survey chainage 140 is
= 528466.280
and the X co-ordinate at survey chainage 145 is
= 528471.177
the X co-ordinate for section chainage 14 will be reported as
528466.280 + ((528471.177 – 528466.280) * (140.246 – 140) / (145 – 140))
= 528466.521
Table 4.9
Calculating section co-ordinates from survey chainage
Example – Fitting crack data
4.5.9
The (start) chainage of individual cracks are also stretched or shrunk on a
section-by-section basis and are reported rounded to the nearest millimetre
(together with the measured offset, length, angle and type). If a crack
spans the boundary between two sections, it is reported only in the section
in which the start of the crack was recorded. (It should be noted that the
start chainage, angle and length of the crack may mean that the end of the
crack is beyond the length of that section.) If the chainage at the start of a
crack lies exactly on the boundary between two sections, it is reported in
the second section only (at section chainage 0).
Figure 4.8
Fitting crack data
For Section A,
The stretch/shrink factor is 58 / (183.255 – 126.561) = 1.0230359.
Each crack with a survey chainage (X) :
greater or equal to 126.561
and less than 183.255
Will be output for Section A at a chainage of (X – 126.561) * 1.0230359
as shown in Table 4.11
Table 4.10
Calculating the stretch / shrink factor
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