Leica Geosystems TPS1100 Professional Series - User Manual - Manual (Page 153)

153
TPS1100 - User Manual 2.2.1en Technical specifications
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∆ D
1
= atmospheric correction [ppm]
p = air pressure [mbar]
t = air temperature [°C]
h = relative humidity [%]
α = 1 / 273.16
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 will be 2 ppm (2 mm / km).
Reduction to mean sea level ∆∆∆∆∆ D
2
The values for ∆ D
2
are always negati-
ve and are derived from the following
formula:
∆ D
2
= reduction to mean sea level
[ppm]
H = height of EDM above sea
level [m]
R = 6378 km
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:
∆ D
3
= projection distortion [ppm]
X = northing, distance from
projection zero line with the
scale factor 1 [km]
R = 6378 km
In countries where the scale factor is
not unity, this formula cannot be
directly applied.
∆ D
2
= -
H
R
· 10 3
∆ D
3
=
X 2
2R 2
· 10 6
Atmospheric correction ∆∆∆∆∆ D
1,
continued