Javad TRIUMPH-LS, User Manual

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147
Localization
of these points as the scale factors become an
extrapolation of the points instead of the more
desirable interpolation.
With all of these considerations satisfactorily answered, I
have surveyed four points common to the 15 I’ve imported.
In Localize, I’ve selected the points on the left side from the
points imported [1101, 1102, 1103, 1104] and the points I
surveyed in Collect on the right side [S101, S102, S103, S104].
Pressing Auto, at the bottom of the screen, automatically
determines by comparison of the internal geometry of
both sets of points how the points should be associated.
With only one or two points the association between the
Design side and the Surveyed side must be done manually
by selecting a point on the left side, selecting a point on the
right side and pressing “Manual” and selecting Horizontal &
Vertical, Horizontal or Vertical.
In this example the imported points did not have meaningful
elevations, therefore the accurate GNSS surveyed elevations
result in high residuals: -3.089, -0.538, -1.729, 5.356. A look
at the localization parameters further reveals the problem
with using a 3D association for these points.
Notice the extremely high inclination values. This is the
plane that best satisfies these points and is far from the
parent plane of the Surveyed Coordinate System (NAVD88).
Returning to the Localize screen by pressing Cancel, and
changing each association one by one from 3D to Horizontal
(indicated by an NE), grays out the delta U column. Now
selecting Setup we see that the North and East Inclinations
are 0. The scale factor is 54 parts per million above 1 and
the rotation is counter-clockwise 11°59’52”. These values
can be edited if desired by checking the box on the left side
and changing the values as desired. The residuals on the
Localization screen will update to reflect these changes. The
scale factor shown is based on ellipsoid heights determined
by survey, so the design point elevations have no impact on
the scale factor.