QUAD: Quadrangle Definition
This record specifies the coordinates (latitudes and longitudes) of a quadrangle (area between two parallels of latitude and two meridians of longitude). A QUAD record is used to define the area in which a particular map projection is valid.
Before a QUAD record is encountered, the valid area for map projections is the entire globe. A QUAD record with all values of zero (0.0 or blank), sets the quadrangle to the entire globe.
The format of the QUAD record is as follows:
Columns 002-005: QUAD
Columns 011-011: North (n) or south (s) indicator for from-latitude
Columns 012-014: Degrees of from-latitude
Columns 016-017: Minutes of from-latitude
Columns 019-019: North (n) or south (s) indicator for to-latitude
Columns 020-022: Degrees of to-latitude
Columns 024-025: Minutes of to-latitude
Columns 027-027: East (e) or west (w) indicator for from-longitude
Columns 028-030: Degrees of from-longitude
Columns 032-033: Minutes of from-longitude
Columns 035-035: East (e) or west (w) indicator for to-longitude
Columns 036-038: Degrees of to-longitude
Columns 040-041: Minutes of to-longitude