LEICA TPS1200 - Manual (Page 208)

208 TPS1200 Technical Data
Reduction to mean
sea level ΔD
2
The values for ΔD
2
are always negative and are derived from the following formula:
Projection
distortion ΔD
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.
ΔD
2
Reduction to mean sea level [ppm]
H Height of EDM above sea level [m]
R 6.378 * 10
6
m
TPS12_053
ΔD
2
= -
H
R
· 10
3
ΔD
3
Projection distortion [ppm]
X Northing, distance from projection
zero line with the scale factor 1 [km]
R 6.378 * 10
6
m TPS12_054
ΔD
3
= -
X
2
2R
2
· 10
3