Spectra Precision Survey Pro v4.6 Recon and Nomad User Manual - Manual (Page 300)

User’s Manual – GPS Mode
290
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. This tilt approximates what a geodosist would
call '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.
Vertical Calibration and Geoid Modeling
If you do not use a geoid model, vertical localization will solve for
slope and separation using the measured heights and the control
elevations. If you do use a geoid model, vertical localization will solve
for the separation between the geoid elevation and your control
elevation. Geoid elevations are computed from measured heights and
geoid undulation using the height equation (see Page 240):
h = H + N
Fig. 9: Vertical Localization
Three control points calculate a plane to model the deflection and shift
between the geoid and ellipsoid surface.
Ellipsoi
d Surface
Geoid S
urface
Separation
Normal
to Geoid
Normal to
Ellipsoid
Deflection (a,b)