Reference Manual Owner manual

Survey Menu
R-153
Note: Typically Left Edge of Center is selected when performing a sun
shot in the northern hemisphere and Center is selected for star shots.
Corrections : displays which corrections are currently
selected with an N for no, or a Y 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.
: is a shortcut to the Date/Time Settings screen (Page R-52).