View Full Version : What's this guy scanning for?

14th Dec 2014, 00:46
I've been watching this Cessna doing these back and forth sweeps across Surrey since before 2200 on Saturday 14/12/2014; he only just going home at 00:44.
They Can't be updating ground photography in the pitch dark; any ideas?
Ordnance Survey? Would radar topography or laser topography need to be done with tracks as small as 500m apart, or even work, considering they're at 7000 feet?

Or Google sniffing for WiFi?


14th Dec 2014, 13:15
Using LIDAR.

From Blom UK Blog (http://www.blom-uk.co.uk) air ops unit blog ( in 2011)

"The beauty of a LiDAR system means that it doesn’t care whether its day, night, dawn or dusk.
The limitation phrase used during traditional aerial photography is “sun angle” – Thankfully “sun angle” isn’t in a LiDAR’s dictionary.
Night survey flying isn’t a new experience for me but watching the sun set (and rise) whilst acquiring data is a different experience. There are lots of advantages to night flying: it’s normally quiet from an air traffic point of view, convective cloud disappears, and it’s normally a lot smoother than daytime."

14th Dec 2014, 13:34
Or they could be using infrared to see whose houses still need extra insulation?

14th Dec 2014, 13:43
Filling in the gaps left by daytime chemtrails ?


14th Dec 2014, 14:01
Mechta almost has it right.

They are looking for hot roofs that indicate cannabis farms.

14th Dec 2014, 14:48
Them TV licence snoopers just got a new toy.

14th Dec 2014, 15:01
......maybe checking if you've got planning permission for that shed?

wings folded
14th Dec 2014, 20:14
What's this guy scanning for?

A fee.

14th Dec 2014, 21:47
Well REV4LF is a Cessna owned and operated by RVL group out of EMA. They do a lot of work for Ordnance Survey as well as a load of work for DEFRA and I also hear they do work for the EU version of DEFRA keeping tabs on farmers because of the various EU subsidies.

I would imagine that at night, in the dark, tracks that close it's likely that some big property developer is planning a major development in the area and wants detailed ground level surveys carrying out over a large area. I don't think OS would need ground level surveys that detailed and I can't think of many other reasons for a survey that detailed that can be done at night.

Plus, with Heathrow and Gatwick not a million miles away there'll be a lot less issues from an Air Traffic perspective with them operating back and forth runs in the same area.

14th Dec 2014, 23:40
Farnborough to Leatherhead including Pirbright, Mayford, Send and Ripley:-


DEFRA? :confused:

15th Dec 2014, 07:45
There's been a number of these surveys by RVL in the area recently, there was an Islander around Croydon late one evening last week and I noticed a Cessna 310 on FR24 doing wee hour runs in the Gatwick area a few months back.

15th Dec 2014, 08:17
You can also use IR surveys to spot leaks in underground pipes.

At night its colder so you get a better temp gradient.

A A Gruntpuddock
15th Dec 2014, 08:34
We heard a lot of helicopter low-flying one night.

Next day, house across the road was raided & lots of cannibis plants removed from attic.

15th Dec 2014, 13:39
A Huey in civilian colours (dark blue, even darker blue or black stripe) with a large pack - stretcher-sized - strapped to the RH skid was flying grid patterns over the house last Saturday. There were a number of probes and structures protruding from the front end package. Each line flown was about 20-30m parallel to the previous one, ending up over the Bay.

Not pollution as their ain't none here.

15th Dec 2014, 17:59
Maybe he's looking where the ex-wife
lives so he can shag his new girlfriend
over her roof in his spanky Cessna.

He's probly got a copilot with him as
one can't trust a Titan autopilot when
doing anything remotely mile-highish.