Spectra Precision Survey Pro v4.5 Ranger User Manual - Manual (Page 255)

GPS Module
245
b. When the rover does not receive the base antenna
information, and the base point exists in the job file,
Survey Pro calculates the antenna from the base
height and the reference position antenna phase
center height. The antenna Measure To displays
Calced. by SP,
and the Measured field displays the
calculated value.
c. When the rover does not receive the base antenna
information, and the base point is new in Survey Pro,
you are prompted to enter the known antenna height
in order to store the new point on the ground, or leave
the antenna height at 0.0 to store the new point at the
base antenna phase center. The antenna Measure To
will display Entered in SP, and the Measured edit box
is enabled for you to enter the value.