secant to the ellipsoid to lessen the effects of distortion. The location of the lines of secancy vary between DRAFT 3-11 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 MERCATOR TRANSVERSE MERCATOR OBLIQUE MERCATOR PARALLEL STRAIGHT LINES UNEQUALLY SPACED PARALLEL STRAIGHT LINES EQUALLY SPACED 90° CONSTANT ANGLE (RHUMB LINE) CURVED LINE (EXCEPT EQUATOR AND MERIDIANS) STRAIGHT LINE MID-LATITUDE CYLINDER TANGENT AT EQUATOR CENTER OF SPHERE (FOR ILLUSTRATION ONLY) INCREASES AWAY FROM EQUATOR MATHEMATICAL DEAD RECKONING AND CELESTIAL (SUITABLE FOR ALL TYPES) YES CURVES CONCAVE TOWARD NEAREST POLE COMPLEX CURVES CONCAVE TOWARD CENTRAL MERIDIAN 90° VARIABLE ANGLE CURVED LINE CURVED LINE CENTER OF SPHERE (FOR ILLUSTRATION ONLY) INCREASES AWAY FROM MERIDIAN OF TRUE SCALE MATHEMATICAL GRID NAVIGATION YES CYLINDER TANGENT AT CENTRAL MERIDIAN FOR GK GRID; SECANT AT CENTRAL MERIDIAN FOR UTM GRID. SINE LINES CURVED LINES 90° VARIABLE ANGLE CURVED LINE CENTER OF SPHERE (FOR ILLUSTRATION ONLY) INCREASES AWAY FROM GREAT CIRCLE OF TRUE SCALE MATHEMATICAL CHARTS OF GREAT CIRCLE PATHS YES CYLINDER CAN BE TANGENT OR SECANT; DEPENDANT ON THE USE.