coaltituden.

1658 J. Collins Sector on Quadrant 125 The first Ark was more then half the coaltitude.

1723 E. Stone tr. N. Bion Constr. & Principal Uses Math. Instruments vii. ii. 205 The Sum is the Zenith Distance, or Co-altitude of the Sun's upper Limb.

1833 J. F. W. Herschel Astronomy i. 62 The angle PAZ, between the pole and the zenith,..is the co-altitude (complement to 90° of the altitude) of the pole.

1902 Bull. Amer. Geogr. Soc. 34 296 The co-altitude, AB, of the observed celestial body.

1993 Jrnl. Amer. Oriental Soc. 113 366/2 The great circle distance from observer to Geographical Position in angular units gives the coaltitude (90° − altitude).

1961 Aerospace Engin. Sept. i. 48/3 Breakaway maneuvers are most critical when the interceptor carries a semiactive weapon with a nuclear warhead and attacks a co-altitude target.

1964 Interceptor Oct. 14/2 One of our flight commanders presented a ‘point system’ for scoring intercepts... Basically, it works like this: Fronts are worth more than sterns and snap-ups more than co-altitude.

1968 MAC Flyer June 22/3 In the case of a co-altitude situation, one aircraft is told to climb and the other to descend.

1983 Aviation Week & Space Technol. (Nexis) 23 May 96 The radar..does not have a look-down capability, but is a coaltitude sensor and has a look-up capability.

2004 J. Sherwood Afterburner viii. 119 With standard radar, one needed to be at co-altitude or, better yet, below the bogey's altitude, to spot a MiG.