Collocations for surveillance - noun

close, constant, regular, round-the-clock, routine
covert, secret
aerial, electronic, Internet, satellite, video
CCTV, closed-circuit television (both esp. BrE)
military, police
health, medical

be under
The suspects are under police surveillance.

keep sb/sth under, place sb/sth under, put sb/sth under
The country's borders are kept under constant surveillance.

carry out, conduct, do
The army carried out covert surveillance of the building for several months.

increase, reduce

camera, device, equipment
footage, tape (AmE), video
The images were covertly captured on surveillance tape.

method, operation, programme/program, system
aircraft
flight
team