numerical map
digital map
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ii. A representation, in digital form, of discrete points on the earth's surface. Also called a numerical map.
dihedral
i. The positive acute angle between the lateral axis of an airplane and a line through the center of a wing or horizontal stabilizer. A dihedral is normally associated with a low-wing aircraft, although some dihedral angles may be incorporated into high-wing aircraft as well. A dihedral increases the lateral stability of an airplane.
ii. The angular difference between the chords of the wing and the tailplane. This is normally referred to as longitudinal dihedral.