Projection : Universal Transverse Mercator
General class : cylindrical
Characteristics: conformal
: rectangular coordinates
Earth model : only supported ellipsoids or spheres
(i.e. E000 to E019)
Universal Transverse Mercator projection requires a zone to be
specified or a sample point in geographic coordinates from which
a zone can be derived. Once the zone is known, the central
meridian can be derived for the zone. If a zone is specified
it would be in MAPUNITS string. Any of the following are valid:Defining the MAPUNITS:
EASI>mapunits="utm 11" ! Standard name and zone EASI>mapunits="utm 11 m" ! Standard name, zone and row EASI>mapunits="utm 11 m e0" ! Standard name, zone, row and ellipsoidIf the zone is not defined in the MAPUNITS string, a sample point can be input with PROLONG and PROLAT. For example:
MapUnits "utm" TrueOriginLongitude "117 w" TrueOriginLatitude " 33 n"If the UTM zone, PROLONG and PROLAT are not defined, but (BX1 and BY1) or (BX2 and BY2) define 'LONG/LAT' point(s), one of these can be used to derive the UTM zone. (If both (BX1 and BY1) and (BX2 and BY2) are defined, (BX1 and BY1) is used.)
If the UTM zone is derived from a sample point and the longitude for the point is shared between zones, the eastern-most zone is returned. For example, if prolong="174w", the assumed zone is UTM zone 2, not UTM zone 1. Any confusion can be avoided, by picking a sample point in the zone and not on the zone border.
Other parameters: None
Possible errors:
E331, "Invalid earth model defined for the projection"