Leica MS50 - Page 95

MS50/TS50/TM50, Technical Data
95
Index n
The index n is calculated from the formula of Barrel and Sears, and is valid for:
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.
Type Index n Carrier wave [nm]
MS50 with R2000
(Wave Form Digitiser)
1.0002863 658
TS50/TM50 with R1000
Combined EDM (Phase Shift
/ System Analyser)
Air pressure p: 1013.25 mbar
Air temperature t: 12 °C
Relative air humidity h: 60 %
Formula for visible red laser
· 10
x
4.126 · 10
-4
· h
-
0.29535 · p
ΔD
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
ΔD
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
ΔD
3
=
X
2
2R
2
· 10
6