TS12P, Technical Data
69
Formulas
D
1
Atmospheric correction [ppm]
p
Air pressure [mbar]
t
Air temperature [°C]
h
Relative humidity [%]
x
(7.5 * t/(237.3 + t)) + 0.7857
If the basic value of 60 % relative humidity as used by the EDM is retained, the
maximum possible error in the calculated atmospheric correction is 2 ppm, 2 mm/km.
Reduction to mean
sea level
D
2
The values for
D
2
are always negative and are derived from the following formula:
Projection
distortion
D
3
The magnitude of the projection distortion is in accordance with the projection system
used in a particular country, for which official tables are generally available. The
following formula is valid for cylindrical projections such as that of Gauss-Krüger:
In countries where the scale factor is not unity, this formula cannot be directly applied.
Formula for visible red laser
· 10
x
4.126 · 10
-4
· h
-
0.29535 · p
Δ
D
1
= 286.338 -
002419_002
1
273.15
D
2
Reduction to mean sea level [ppm]
H
Height of EDM above sea level [m]
R
6.378 * 10
6
m
TS_106
Δ
D
2
= -
H
R
· 10
6
D
3
Projection distortion [ppm]
X
Easting, distance from projection zero line with the
scale factor 1 [km]
R
6.378 * 10
6
m
TS_107
Δ
D
3
=
X
2
2R
2
· 10
6
