circle (latitude less than 81° 07') is shorter than the same line when it is projected onto the plane (AB is shorter than A'B). d.  Scale Factor.  The scale factor used with the Polar Stereographic Projection is Exact (1.000 or Unity) along the line of secancy (81° 07' Lat).  It decreases to 0.994 at the pole and increases to 1.0016076 at 80° latitude.  The scale factor reaches its maximum value of 1.0023916 at 79° 30' latitude.  Scale factor is constant along any given parallel.  See Figure 3-13.            3-9  Overlapping Projections a.  General.  For military mapping purposes, the primary projections to be used are the Polar Stereographic Projection in the polar regions and the Transverse Mercator Projection between the polar regions.  It is likely that a contingency may cross between these projections in one direction or the other. In order to reduce the amount of confusion caused by crossing the established limits of a projection, an overlap between the two projections is used.   b.  Transverse Mercator.  The Transverse Mercator Projection is normally considered to cover areas between 80° S latitude and 84° N latitude.  However, in paragraph 3-6b it was stated that this projection extends to 80° 30' S and 84° 30' N latitudes.  The 30' extension is an overlap into the Polar Stereographic Projection.   c.  Polar Stereographic.  The Polar Stereographic Projection is normally considered to cover the polar regions south of 80° S latitude and north of 84° N latitude.  However, in paragraph 3-8a it was stated that this projection extends to 79° 30' S and 83° 30' N latitudes.  The 30' extension is an overlap into the Transverse Mercator Projection. DRAFT 3-9 Figure 3-16  Oklahoma Lambert Projection; North and South Zones. OKLAHOMA 102° 101° 100° 99° 98° 97° 96° 95° 33° 34° 35° 36° 37° NORTH ZONE 35° 34' NORTH ZONE 36° 46' 33° 56' SOUTH ZONE SOUTH ZONE 35° 14' MERIDIANS AND PARALLELS STANDARD PARALLELS