Become a Patron and get help from Pros
A perspective azimuthal projection in which the projecting lines, emanating from a point at infinity, are perpendicular to a tangent plane. The projection is used chiefly in navigational astronomy for inter converting coordinates of the celestial equator and horizon systems. Also called ORTHOGONAL PROJECTION.

Related Terms


1. A small pointed or tapered piece, often cylindrical, used to pin down or fasten parts. 2. A projection used to hang or support objects.


1. An arrangement of fixed resistors used to reduce the strength of a radio-frequency or audio-frequency signal by a desired fixed amount without introducing appreciable distortion. Also known as fixed attenuator. 2. See terminal area. 3. A layer of material used as a cushion or for protection. 4. A projection of excess metal on a casting forging, or welded part. 5. An area within an airstrip or airway that is used for warming up the motors of an airplane before takeoff. 6. A block of stone or masonry set on a wall to distribute a load that is concentrated at that portion of the wall. Also known as padstone. 7. That portion of an airstrip or airway from which an airplane leaves the ground on takeoff or first touches the ground on landing. 8. See helipad.


A device for projecting positive transparent pictures from glass or film onto a reflecting screen; it consists of a concentrated source of light, a condenser system, a holder (or changer) for the slide, a projection lens, and (usually) a blower for cooling the slide. Also known as slide projector.


1. Projection of a tread of a stair beyond the riser below it. 2. A transverse, horizontal motion of a locomotive that exerts a lateral force on the track.


A type of joint, principally used for wood, in which a hole, slot, or groove (mortise) in one member is fitted with a projection (tenon) from the second member.


The diameter of the circle described by the outermost projection of a vehicle when the vehicle is making its shortest possible turn.


1. A device whose light transmission can be made to vary in accordance with an externally applied electrical quantity, such as volatage, current, electric field, or magnetic field, or an electron beam. 2. Any directview electronic display optimized for reflecting or transmitting an image with an independent collimated light source for projection purposes.


The projection of circular motion on a diameter of the circle of such motion. Simple harmonic motion is produced if the circular motion is of constant speed. The combination of two or more simple harmonic motions results in compound harmonic motion.


The great circle of the celestial sphere midway between the zenith and nadir, or a line resembling or approximating such a circle. The line where earth and sky appear to meet, and the projection of this line upon the celestial sphere, is called the visible or apparent horizon. A line resembling the visible horizon but above or below it is called a false horizon. The circle of the celestial sphere-formed by the intersection of the celestial sphere and a plane perpendicular to the zenith-nadir line is called sensible horizon if the plane is through any point, such as the eye of an observer; geoidal horizon if through any sea-level point; and celestial or rational horizon if through the center of the earth. The geometrical horizon was originally considered identi- cal with the celestial horizon, but the expression is now more commonly used to refer to the intersection of the celestial


A chart on the Lambert conformal projection

Related questions

MarineProHelp 2018 - 2021