projections.  Many Oblique Mercator Projections exist; however, only two will be discussed in this manual: DRAFT 3-12 CHARACTERISTICS PARALLELS MERIDIANS APPEARANCE OF PROJECTION ANGLE BETWEEN PARALLELS & MERIDIANS STRAIGHT LINE CROSSES MERIDIANS GREAT CIRCLE RHUMB LINE DISTANCE SCALE GRAPHIC ILLUSTRATION ORIGIN OF PROJECTORS DISTORTION OF SHAPES AND AREAS METHOD OF PRODUCTION NAVIGATIONAL USES CONFORMAL GNOMONIC POLAR GNOMONIC POLAR STEREOGRAPHIC STRAIGHT LINES VARIABLE ANGLE (GREAT CIRCLE) CENTER OF SPHERE INCREASES AWAY FROM CENTER OF PROJECTION GRAPHIC OR MATHEMATICAL GREAT CIRCLE NAVIGATION AND PLANNING NO CONCENTRIC CIRCLES UNEQUALLY SPACED STRAIGHT LINES RADIATING FROM THE POLES 90° CURVED LINE CENTER OF SPHERE INCREASES AWAY FROM POLE NO 90° CURVED LINE POLAR NAVIGATION OF ALL TYPES YES PLANE CAN BE TANGENT OR SECANT; DEPENDANT ON THE USE. CONIC SECTIONS (CURVED LINES) VARIABLE ANGLE STRAIGHT LINE CURVED LINE VARIABLE ANGLE (GREAT CIRCLE) STRAIGHT LINE GRAPHIC OR MATHEMATICAL GREAT CIRCLE NAVIGATION AND PLANNING CONCENTRIC CIRCLES UNEQUALLY SPACED STRAIGHT LINES RADIATING FROM THE POLES VARIABLE ANGLE (APPROXIMATES GREAT CIRCLE) APPROXIMATED BY STRAIGHT LINE NEARLY CONSTANT EXCEPT ON SMALL SCALE CHARTS OPPOSITE POLE DECREASES AWAY FROM POLE GRAPHIC OR MATHEMATICAL