Spectra Precision Survey Pro v3.80 Recon iPAQ Reference Manual User Manual

Page 111

Survey Menu

R-105

Note: Typically

Left Edge of Center

is selected when performing a sun

shot in the northern hemisphere and

Center

is selected for star shots.

&RUUHFWLRQV : displays which corrections are currently

selected with an

for no, or a

for yes. When tapped,

the Corrections screen opens where the following
corrections are configured.

•

;

Non-linear Declination Correction

: applies a

correction for the linear interpolation of the
declination of the sun for the time that an
observation is taken. This error is usually
negligible, but is removed when this is checked.
(This should only be checked when performing
sun shots.)

•

;

Correct to State Grid

: when selected, the

computed azimuth is referenced from the local
State Plane grid rather than true north.

•

;

Center Meridian

Zone Constant

: these values are used to

adjust the computed azimuth to the local State Plane grid.
Appendix A lists these values for the United States.

GHA0

: is the Greenwich Hour Angle of the sun at zero hour Universal

Time, Greenwich, on the current date.

Decl0

: is the declination of the sun at zero hour on the current date.

GHA24

: is the Greenwich Hour Angle of the sun at zero hour

Universal Time, Greenwich, on the following day (24-hours later).

Decl24

: is the declination of the sun at zero hour on the following day.

Solar Semi-Diameter

: is the semi-diameter of the sun, expressed in

minutes and seconds.