Spectra Precision ProMark Field Software - Manual (Page 50)

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working area. The higher the number of points known in the
local system, the higher the redundancy and the more
accurate the determination of the unknown local system.
Once the local system is determined and used, all the points
logged afterwards will be expressed in that system. In this
kind of project, the calibration step should then be performed
in the first place.
Using the Calibration function is a two-step procedure:
1. First you visit each of the known points with your rover,
and when you are there, you enter the known coordinates
in the unknown local system. In the background, the rover
will associate the “fixed” RTK position computed in real
time with the coordinates you enter.
2. Then, when enough points have been logged and the post-
fit residuals are all zero or close to zero (meaning the local
system has been determined successfully), make the local
system the new coordinate system used in the job. The
properties of the job will show that a “fitted” system,
instead of the original one, is now used in the job.
Follow the instructions below to determine the local
coordinate system:
• Create a new job.
• Choose a coordinate system (ENH axis system) that is
suitable for your working area, with a projection that will
stay unchanged in the local coordinate system, once
determined (XYZ axis system). The calibration function is
inaccessible if the selected coordinate system does not
use a projection.
• Take the necessary steps to get a “fixed” position solution
from your rover.
• Go to the first known point and stay static on that point.
• Select Menu > Calibration and tap on the Add button.
• Enter the point ID and its coordinates, as known in the
local system.
You may either select the point from the list of points
stored in the job (using the on-screen
Select Point button)
or directly type in the point ID and its coordinates in the
corresponding fields if this point is not available from the
list of points.
Tell ProMark Field if that point provides reference
coordinates either horizontally or vertically, or both (both
by default).
PT2
PT3
Z
H
E
N
Y
X
PT1