Leica Geosystems GPS System 500 - Technical Reference Manual - Manual (Page 281)

281 11. Applications Technical Reference Manual-4.0.0en
For a 2-Step transformation first the
pre-transformation is applied to
obtain auxiliary cartesian coordi-
nates. Then the specified map
projection is applied on the given
ellipsoid.
For both methods this results in a
temporary auxiliary grid. A 2D
Helmert transformation is then
performed between the auxiliary grid
and the given local system.
The position transformation results
are given first.
Shift dX, dY - Shift along the X and
Y axes.
Rotation - Rotation about the Z axis.
Scale - Scale factor between the two
datums.
Then the Height transformation
information is given.
Slope dH/dX / dH/dY - Slope of the
height interpolation plane when
looking along the X or Y axis.
Shift H0 - Height of the interpolation
plane at the point it intersects the Z
axis.
Origin X0, Y0 - Coordinates of the
center of gravity of points in the
auxiliary local grid.
Use the RMS (F5) key to display
calculated accuracies for each of the
transformation parameters.
Use the SCALE/ ppm (F4) key to
switch between ppm and scale factor
values.
Use the EDIT (F3) key if you wish to
edit the previously calculated 1-Step
or 2-Step parameters.
Shift dX, dY, Rotation, Scale Factr -
The position transformation results
can be edited if required. This may be
necessary in some circumstances
where you have computed a One
Step transformation, but still wish to
use a specific scale or rotation for
example.
Elev Factor - Displays the elevation
factor calculated from the ellipsoidal
height(s) of the common point(s).
Apply Elev - If set to YES the Comb
Factor will be calculated as Scale
Factor x Elev Factor. If set to NO the
Comb Factor will be equal to the
Scale Factor of the original calcula-
tion.
In COORDSYS\ Edit Parameters
press ABORT (F5) to go back without
any changes or press CONT (F1) to
accept the Comb Factor and the
other 1-Step/ 2-Step parameters you
have changed.