Leica Technical Data TPS1200 208, Reduction to mean, Sea level ΔD2, Projection, Distortion ΔD3

Technical Data TPS1200 208

Reduction to mean

The values for ΔD2 are always negative and are derived from the following formula:

sea level ΔD2

ΔD2= - H · 103

R

TPS12_053

ΔD2 Reduction to mean sea level [ppm]

HHeight of EDM above sea level [m] R 6.378 * 106 m

Projection	The magnitude of the projection distortion is in accordance with the projection
distortion ΔD3	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:

ΔD3= - X22 · 103 2R

TPS12_054

ΔD3 Projection distortion [ppm]

XNorthing, distance from projection zero line with the scale factor 1 [km]

R 6.378 * 106 m

In countries where the scale factor is not unity, this formula cannot be directly applied.