Basics of Map Projection 81
80
◦
north and south of 80
◦
south are mapped using UPS (Universal Polar
Stereographic) projection. The figure shows the UTM zones indexing system.
Each zone index constitutes a ‘number-alpha’ index scheme where the number
refers to the 8
◦
zone and / or the column designator and the character (‘A’-
‘X’) are used as the row designator of the UTM zones. Each UTM zone has a
central meridian which has a scale factor of 0.9996.
In order to avoid negative coordinates for portions located west of the cen-
tral meridian the central meridian has been assigned a (false) easting value of
5000,000 (meters). The equator has been given a northing value of ‘0’ meter.
For measuring the positions north of the equator a (false) northing value