A map projection in which the surface of a sphere or spheroid, such as the earth, is conceived as developed on a tangent cylinder, which is then spread out to form a plane. |
A map projection in which the surface of a sphere or spheroid, such as the earth, is conceived as developed on a tangent cylinder, which is then spread out to form a plane. |
Related Terms |
SIMPLE CONIC MAP PROJECTIONA conic map projection in which the surface of a sphere or spheroid, such as the earth, is conceived as developed on a tangent cone, which is then spread out to form a plane. |
POLYCONIC MAP PROJECTIONA conic map projection in which the surface of a sphere or spheroid, such as the earth, is conceived as developed on a series of tangent cones, which are then spread out to form a plane. A separate cone is used for each small zone. This projection is widely used for maps but seldom used for charts, except for survey purposes. It is not conformal. |
STEREOGRAPHIC MAP PROJECTIONA perspective, conformal, azimuthal map projection in which points on the surface of a sphere or spheroid, such as the earth, are conceived as projected by radial lines from any point on the surface to a plane tangent to the antipode of the point of projection. Circles project as circles except for great circles through the point of tangency, which project as straight lines. The principal navigational use of the projection is for charts of the polar regions. Also called AZlMUTHAL ORTHOMORPHIC MAP PROJECTION. |
RECTANGULAR PROJECTIONA cylindrical map projection with uniform spacing of the parallels. This projection is used for the star chart in the Air Almanac. |
MILITARY GRID REFERENCE SYSTEMA system which uses a standard-scaled grid square, based on a point of origin on a map projection of the earth’s surface in an accurate and consistent manner to permit either position referencing or the computation of direction and distance between grid positions. |
CYLINDRICAL CHARTA chart on a cylindrical map projection |
PERSPECTIVE MAP PROJECTIONA map projection produced by the direct projection of the points of the ellipsoid (used to represent the earth) by straight lines drawn through them from some given point. The projection is usually made upon a plane tangent to the ellipsoid at the end of the diameter joining the point of projection and the center of the ellipsoid. The plane of projection is usually tangent to the ellipsoid at the center of the area being mapped. he analytical expressions that determine the elements of the projection. If the point of projection is at the center of the ellipsoid, a gnomonic map projection results; if it is at the point opposite the plane’s point of tangency a stereographic map projection; and if at infinity (the projecting lines being parallel to each other), an orthographic map projection. Most map projections are not perspective. Also called GEOMETRIC MAP PROJECTION. |
MAP PROJECTIONA systematic drawing of lines on a plane surface to rep- resent the parallels of latitude and the meridians of longitude of the earth or a section of the earth. A map projection may be established by analytical computation or may be constructed geometrically. |
GNOMONIC MAP PROJECTIONA perspective azimuthal map projection in which points on the surface of a sphere or spheroid, such as the earth, are conceived as projected by radials from the center to a tangent plane. Great circles project as straight lines. For this reason the projection is used principally for charts for great circle sailing. The projection is neither conformal nor equal area |
OBLIQUE MERCATOR MAP PROJECTIONA conformal cylindrical map projection in which points on the surface of a sphere or spheroid, such as the earth, are developed by Mercator principles on a cylinder tangent along an oblique great circle. Also called OBLIQUE CYLINDRICAL ORTHOMORPHIC MAP PROJECTION. |
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