In message , at 18:47:06 on
Mon, 18 Sep 2017, Charles Ellson remarked:

The moveable cameras tend to be at strategic points where they can cover
may different routes. The panning and tilting can be automatic on a timer.
Such cameras are more for preventing crime than detecting it.

each moveable camera is likely to augment several fixed cameras depending
on purpose. When you get to the point of needing to track a specific
target then you probably are needing more moveable cameras (and zoom
lenses).

You've been watching too much "Spooks".

No, I've been working in one of many areas where that is exactly what
is done when an offender leaves the scene of their crime. They're
generally too thick to go off down a side street so we've often
watched the police with us just waiting for them to walk/run past.

How are the police alerted to the flight of the alleged offender so
soon?

Meanwhile, I was looking at one of the pan/tilt cameras on a street
corner (T-junction) earlier today, and it simply cycles between each of
the three directions every 15-20 seconds.
--
Roland Perry