From WordNet (r) 3.0 (2006) [wn]:
sighting
n 1: the act of observing; "several sightings of enemy troops
were reported"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Sighting \Sight"ing\,
a. & n. from Sight, v. t.
[1913 Webster]
Sighting shot, a shot made to ascertain whether the sights
of a firearm are properly adjusted; a trial shot.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Sight \Sight\, v. t. [imp. & p. p. Sighted; p. pr. & vb. n.
Sighting.]
1. To get sight of; to see; as, to sight land; to sight a
wreck. --Kane.
[1913 Webster]
2. To look at through a sight; to see accurately; as, to
sight an object, as a star.
[1913 Webster]
3. To apply sights to; to adjust the sights of; also, to give
the proper elevation and direction to by means of a sight;
as, to sight a rifle or a cannon.
[1913 Webster]