Spectra Precision Survey Pro v4.6 Ranger User Manual - Manual (Page 118)

User’s Manual – Conventional Mode
108
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
Ellipsoid Scale Factor
This scale factor accounts for the height of the ground above the
reference surface (the ellipsoid). This scale factor is defined
geometrically: Consider the following diagram:
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.
Fig. 3: Transverse Mercator Mapping Plane
A side view of the cylinder shows the effect of scale
distortion.