Spectra Precision Survey Pro v4.5 Recon and Nomad Reference Manual - Manual (Page 245)

Survey Menu – GPS Module
R-237
Projection Calculator – Rotation
Convergence : displays the computed rotation from
geodetic north to grid north.
Rotation : displays the computed rotation from grid north
to geodetic north.
< Back : returns you to the first Projection Calculator
screen.
Accept : copies the two computed values to past results
and returns you to the first Projection Calculator screen.
Projection Calculator – Scale – Height Correction
Ellipsoid Height : is where you enter the WGS84
ellipsoid height for your current location. This value
will be used to calculate the height above the terrain
component of the scale factor. This is sometimes referred
to as the sea level correction.
< Back : returns you to the first Projection Calculator
screen.
Solve > : takes you to the final screen.