y-axis. [JP 1-02] (DoD) A vertical axis in a system of rectangular coordinates; that line on which distances above and below (north or south) the reference line are marked, especially on a map, chart, or graph.
Y-scale. [JP 1-02] (DoD, NATO) On an oblique photograph, the scale along the line of the principal vertical, or any other line inherent or plotted, which, on the ground, is parallel to the principal vertical.
yaw. [JP 1-02] (DoD, NATO)
l The rotation of an aircraft, ship or missile about its vertical axis so as to cause the longitudinal axis of the aircraft, ship or missile to deviate from the flight line or heading in its horizontal plane.
l The rotation of a camera or a photograph coordinate system about either the photograph z-axis or the exterior z-axis.
l Angle between the longitudinal axis of a projectile at any moment and the tangent to the trajectory in the corresponding point of flight of the projectile.
Yellow Veil. AN/ALQ-167(V) Jamming pod
yield. See nuclear yields.