Any idea what this device is?

[Crispy]

yes, I think we can all slap ourselves on the back for identifying a cable tie

 

[free spirit]

i think it's a microwave link to send the information to GT

yep

I'm inclined to rule out microwave because from the sound of it (and the look of it), it's been lashed onto a cherry-picker, and alignment issues would be a nightmare.

only a minor nightmare, but with a bit of trial and error it'd be pretty easy to line up.

very easy to block the signal as well mind if anyone felt the urge - well, easy if you sus out the precise line of site you're needing to block, which would be fairly difficult without someone on the inside to let you know when you'd blocked the signal.

 

[MikeMcc]

If it's a waveguide horn antenna then the beamwidth is going to be pretty wide (theres no reflecting dish) so alignment and blocking issues would be pretty minor, but effective range would be crap.

The large connector at the back looks like an IEC power connector (i.e. kettle lead), leaving three other cables. That sounds suspiciously like composite video signal.

 

[BigTom]

That sounds suspiciously like composite video signal.

composite video is one cable. I don't think it's video, unless the big connector that is by itself is a bnc connection. I'd be surprised if it was RGB becuase I can only think of RGBHV as a standard video connection.. video tends to be one cable (composite), 2 cables (YV / s-video) or 5 (rgbhv / vga).
One of the cables could be a control cable and two of them YV cables plus the power ot make four cables, but I agree with fridgemagnet, it just doesn't look like a video camera.

 

[WouldBe]

The large connector at the back looks like an IEC power connector (i.e. kettle lead), leaving three other cables. That sounds suspiciously like composite video signal.

Transmit
Recieve
Control cable (probably)

 

[MikeMcc]

Thinking about it again, I'll take a bet that it's an RF receiver. Spiral antenna (very wide bandwidth) in a weatherproof plastic can, mains powered RF receiver, with the rest of the cables providing controls and taking data down to whatever is analysing it. If that's the case then I'll bet it's something to do with someone a bit more sneaky-beaky than normal plod, NCS / NCIS / SOCA, or MI5.

They build a fair bit of their own kit, I had an (unsuccessful) interview for a techie job with NCS when I left the Army. A lot of the questions were about RF receivers.