Understanding Map Projections

UNIVERSAL POLAR STEREOGRAPHICAreaThe farther from the pole, the greater the area scale.DirectionTrue direction from the pole. Local angles are correcteverywhere.DistanceIn general, the scale increases with distance from thepole. Latitude 81°06'52.3" N or S has true scale. Thescale closer to the pole is reduced.The central meridian is 90° S. The latitude of standard parallelis 81°06'52.3" S. The false easting and northing values are2,000,000 meters.DESCRIPTIONAlso known as UPS.This form of the Polar Stereographic projection mapsareas north of 84° N and south of 80° S that aren’tincluded in the UTM Coordinate System. Theprojection is equivalent to the polar aspect of theStereographic projection of the spheroid withspecific parameters. The central point is either theNorth Pole or the South Pole.LIMITATIONSThe UPS is normally limited to 84° N in the northpolar aspect and 80° S in the south polar aspect.USES AND APPLICATIONSConformal mapping of polar regions.Used for mapping polar regions of the UTMcoordinate system.PROJECTION METHODApproximately (for the spheroid) planar perspectiveprojection, where one pole is viewed from the otherpole. Lines of latitude are concentric circles. Thedistance between circles increases away from thecentral pole. The origin at the intersection ofmeridians is assigned a false easting and falsenorthing of 2,000,000 meters.LINES OF CONTACTThe latitude of true scale, 81°06'52.3" N or S,corresponds to a scale factor of 0.994 at the pole.LINEAR GRATICULESAll meridians.PROPERTIESShapeConformal. Accurate representation of local shape.92 • Understanding Map Projections