Spectra Precision Survey Pro v4.6 Ranger User Manual - Manual (Page 227)

GPS Overview
217
E
lli
ps
oi
d
Mapping Plane
K=0.9996
K=1.0 K=1.0
Central Meridian
K>1.0 K>1.0 K<1.0
Distance on Ellipsoid
Distance on Map
• Universal Transverse Mercator Projection
The scale factor at the central meridian (CM) is 0.9996. The scale
factor is 1.0 approximately 170-km east and west of the CM. The
scale factor is less than one between the CM and the point of
tangency. The scale factor is greater than one beyond the point of
tangency. Therefore, at the central meridian, a geodetic distance of
100m scales into a mapping plane distance of 99.96m.
Ellipsoid
Terrain
h
Mapping
Plane
Fig. 3: Transverse Mercator Mapping Plane
A side view of the cylinder shows the effect of scale
distortion.
Fig. 4: Localization Stereographic Mapping Plane
A side view of the ellipsoid and stereographic mapping
plane show the scale calculated for ground distances at
the base height.