Spectra Precision Survey Pro v3.80 Recon GPS User Manual - Manual (Page 48)

GPS User’s Manual
44
Mapping Plane Mode:
Scale: is the scale difference between the intermediate mapping
plane using the autonomous GPS position and the actual mapping
plane control coordinates. Scale should be very close to 1.0. A value
of 1.0 corresponds to grid distances on the selected conformal
mapping plane.
A scale value significantly greater or smaller than 1.0 may indicate
problems with the control point accuracy and/or the control
measurement precision. It might also indicate a scale bias in the
control point plane coordinates, which you may want to correct by
solving a fixed scale transformation.
Rotation: will be 0.0 for Localized map projections.
Origin: is the coordinate on the intermediate mapping plane of the
centroid of the control points. It is calculated by average of (N,E)
coordinate of all control points.
Translation: is the shift between the origin and the local coordinate
of the centroid of the control points. This value represents the shift
from the inaccurate autonomous GPS start point and the actual
coordinates for that position. This value should be less than 15 m
with Selective Availability turned off.
Vertical:
Slope: is the North and East tilt of the inclined plane
adjustment. These values are given in parts per million,
and represent the radian angle values of the deflection
between the ellipsoid normal and the local gravity
vector. These values are also called 'deflection of the
vertical'.
Separation: is the shift between the local elevation and
the vertical reference surface (geoid elevations when
using a geoid model or ellipsoid height when using
Localization vertical only).
Origin: is the local coordinate of the first point used in
the control point list. The slope values are applied from
this point.