Computing in Geographic Information Systems

50 Computing in Geographic Information Systems

For geo-coding of objects using the UTM system 16 digits are enough to

store the location to a precision of 1 meter, with one digit restricted to a binary

(northern or southern hemisphere), and the first digit of the zone restricted

to 0 to 6 (60 is the largest zone number).

This coordinate system has two real cartographic advantages. First, ge-

ometric computations can be performed on geographic data as if they were

located not on the surface of a sphere but on a plane. Over small distances, the

errors in doing so are minimal, although it should be noted that area compu-

tations over large regions are esp ...