Hi-Target HTS-420R - Grid Factor Settings; Coordinate Calculation Formulas; Distance Calculation Methods

Total Station Manual
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5 After finishing setting,
press [F4](OK) to save settins
and back to previous
menu.Then press the key of
[F3](OK) to save the setting of
EDM and back to the function
of measurement.
[F4]
[F3]
[EDM Setting]
EDM Mode:
Reflector: Prism
P.C. : 30.0 mm
OK
Single
ATOMS Pointer
※1：The range of enter：Temp.（-30℃～60℃），Press.（500hPa～1400hPa）.
※2：The instrument calculates the value of PPM according to the values of
temperature and pressure you enter.
※3：Press [F1](PPM=0) can set the value of PPM to 0.
※4：If instrument supports temperature pressure sensor, you can press [F2] to
receive the values of air pressure, temperature and calculate the correction
valueautomatically.
2.3 Grid factor setting
When calculating the coordinates, the horizontal distance measured must
multiply by the scale factor.
Computation formula
1. Altitude factor=R/(R+ELEV)
R: The average radius of earth
ELEV: mean sea level altitude
2. Scale factor
Scale factor: Scale factor of the station
3. Grid factor
Grid factor=altitude factor×scale factor
Distance calculation
1. Grid distance
HDg=HD×grid factor
HDg：Grid distance
HD：Ground distance
2. Ground distance
HD=HDg/ (Grid factor)
Note:
1. The enter range of the scale factor: 0.99~1.01, the default value is 1.0.