* Aim: To detect any unidentified flying object around the airport
Solution: 
Compare the images from the video camera, with those in the database and ignore the images which are already in the database.

Stype(object) Sxyz(*) 
Smedia_sources(video) media_sources
where
Stype(object) NOT IN
(stype(aircraft) Sxyz(*)
Stype(aircraft)database)

* Aim: To find all the flying airplane(s) at a given time interval t1 and t2
Solution:
Smotion(moving) Stype(airplane) 
Sxy(*) 
S(T)T mod 10 = 0 and T > t1 and T < t2 
Smedia_sources(video)media_sources