Spectra Precision Survey Pro v3.80 Recon iPAQ Reference Manual - Manual (Page 188)

Survey Pro Reference Manual
R-182
SD/ZA to HD/VD
&RJR 6'=$ WR +'9'
The SD/ZA to HD/VD screen will convert a slope distance and zenith
angle to an equivalent horizontal distance and vertical distance.
Slope Dist : is the slope distance to be converted.
Zenith : is the zenith angle to be converted.
HI : is the distance that the total station is above the
ground.
HR : is the length of the rod.
; Earth Curvature Adjust : When checked, the computed
horizontal distance and vertical distance will account for
the curvature of the earth and refraction.