Specifications

FASTER Planning Software
48
The ellipsoidal Earth is used throughout the UTM projection system, but the
reference ellipsoid changes with the particular region of the Earth. A list of reference
ellipsoids (datum) is presented in Table 4.
Datum
Equatorial
Radius [m]
(a)
Polar Radius
[m] (b)
Flattening
(a-b)/a
Use
NAD83/WGS84
6378137
6356752.3142
1/298.257223563
Global
GRS 80
6378137
6356752.3141
1/298.257222101
US
WGS72
6378135
6356750.5
1/298.26
NASA, DOD
International
(1924)
6378388
6356911.9
1/297
Global
Clarke 1866
6378206.4
6356583.8
1/294.98
North
America
Table 4: Datum
The mathematical formulation to convert geographical coordinates to UTM and vice
versa are presented in Appendix 1 showing how GEOtoUTM.m and UTMtoGEO.m
scripts work. In the following picture the polygon drawn in Figure 39 is plotted using
UTM coordinates.
Figure 41:Ridolfi-area.kmz converted in UTM coordinates