EPSG
EPSG guidance note #7.
2002-11-22
Applies to 2D and the horizontal component of 3D ellipsoidal systems.
In the formulas that follow, the coordinate strings are symbolically represented as follows: deg decimal degrees adeg absolute value of decimal degrees ideg integer degrees sdeg signed integer degree min real-number minutes imin integer minutes sec real-number seconds lathem, lonhem hemisphere abbreviation In this conversion the degree parameters remain unchanged in this conversion (both forward and reverse). The hemisphere parameters retain their values but change their positions in their respective coordinate strings. Forward calculation from HDM representation to DMSH representation: imin = INT(min) sec = (min - imin) * 60 Then reorder fields from hem, ideg, imin, sec to ideg, imin, sec, hem. Reverse calculation from DMSH representation to HDM representation: min = imin + (sec / 60) Then re-order fields from ideg, min, hem to hem, ideg, min.