deflection angle

deflection angle

[di′flek·shən ‚aŋ·gəl] (geodesy) The angle at a point on the earth between the direction of a plumb line (the vertical) and the perpendicular (the normal) to the reference spheroid; this difference seldom exceeds 30 seconds of arc. (ordnance) An angle that measures the departure of a moving object from its directed course. The angle of a deflection shot in gunnery, measured between the line of sight to the target and the line of sight to the aiming point.

deflection angle

In surveying, a horizontal angle measured from prolongation of the preceding transit line to the next line; recorded as “right” if clockwise rotation and “left” if counterclockwise.

deflection angle

i. In surveying, a horizontal angle measured from the prolongation of the preceding line to the following line. Deflection angles to the right are positive; those to the left are negative.
ii. In photogrammetry, a vertical angle, measured in the vertical plane containing the flight line by which the datum of any model in a stereo-triangulated strip departs from the datum of the preceding model.
iii. In gunnery, the angle that the aircraft needs to lay ahead of the target aircraft to provide for the time of flight of the weapon to the target. It is normally measured in milliradians.