Let's watch TV instead of radar

[Spitoon]

UK mulls 'radical' shake-up of air traffic control (http://www.bbc.co.uk/news/technology-21373771)

Mmmm, much better idea than using dedicated and managed systems. I guess I'm turning into one of those Luddites that the man from Thales has in mind!

[2 sheds]

The proposed system works by utilising the TV transmitters that are dotted around the UK.
Each will receive the same TV signal but at a slightly different time because of the reflections and interactions with aircraft flying in their vicinity.
The received signals are then compared to the original broadcast, and the difference is used to locate the position of the aircraft.

Could some knowledgeable person elaborate - one of the basic principles is apparent but the Beeb "technology reporter" is a bit sparse with the detail!

2 s

[Tigersaw]

Sounds like a hare brained wide area multilateration proposal whipped up to grab government funding

[Ninja Controller]

Standard navigation charge of £145.50pa could do wonders for reducing airfares.

[eglnyt]

Sounds like a hare brained wide area multilateration proposal whipped up to grab government funding

Far from it. It works and potentially has a number of advantages over conventional radar. The biggest limitation has been range and resolution but last week Indra announced they have built a successful high resolution system. Plenty on the web including wikipedia if you care to look.

[ZOOKER]

Sounds like a scheme to free-up space for mobile phones, so that more people can ring more people and shout. "I'm on the train".
To hell with the safety of those in aeroplanes.
HS2 enabling, isn't it, Mmm?
Marvellous.

[ZOOKER]

And by the way, what will happen when peoples' 42'' Panasonic suddenly switches from Brucies' Strictly Come Dancing From Hell On Ice I'm A Waste Of Carbon Atoms Get Me Out Of Here....
To a close-up of the Ockham hold? :E

[ZOOKER]

eglnyt,
I see a major MATS2 re-write on the horizon.....

Telly Information Service.
Telly Control Service.
Basic Service, i.e. CBBC.
Carol Voordeman Service. :ok:

[DaveReidUK]

Sounds like a scheme to free-up space for mobile phones, so that more people can ring more people and shout. "I'm on the train".You're not wrong there.

"There is an increasing demand for the use of the electromagnetic spectrum and it is likely that the current frequency allocations for PSR, in both the L- and S- bands, will come under threat, with MSPSR offering the potential to provide improved coverage and performance for a smaller frequency allocation."

[Tigersaw]

EGLNYT:
Yes, I'm being a bit cynical tonight :)
Its been bubbling under for many years (eg silent sentry), but I would doubt even the TV broadcast transmitters will be with us in another 20 years, their spectrum also sold off as we move forward to an ever connected all you can eat interwebbery

[canard68]

I think the Air Defence chaps had a system like this in the 1960s.

[Sallyann1234]

The TV broadcast band has recently been reduced to make way for 4g mobile services. Further channels will be removed by 2018.
There is a school of thought that by the early 2020's the majority of TV reception will be either from satellite or over fast broadband, which will make maintenance of the elaborate terrestrial TV network uneconomic and subject to closure.
So it would be inadvisable to base any new service on it.

[DaveReidUK]

I think the Air Defence chaps had a system like this in the 1960s. Come to that, Watson-Watt's original radar trials in the 1930s made use of BBC broadcast transmissions.

Plus ça change.

[chevvron]

1) To do this, the ITU would have to agree, and with some countries having very few TV transmitters, I can't see this happening.
2) There would have to be a 'robust' safety case to get the CAA to agree.
3) The CAA would probably require the signal to be 'clean' ie not carrying any broadcast material. This would negate one of the so-called advantages, as it would require dedicated transmitters, rather than use existing ones. As a 'for instance', the DGPS signal presently transmitted by commercial FM stations is not accessible from aviation GPS' presumably for this same reason.

[rsuggitt]

This is just the same as GPS but with a different reference source, surely ? And surely it means that a receiver in the aircraft will have to work out the position, and then transmit it like mode S ?

[HEATHROW DIRECTOR]

Have you ever seen what happens when there is QRM to the GPS system? And watching ADS-B equipped aircraft is fun too! What is wrong with the tried and tested radar system currently in use? Presumably extra links would have to be installed from the TV sites to the ATCCs and airfields?

[landedoutagain]

Prestwick Centre TV has been U/S for over a week, cant see that being sustainable if the radar pic went the same way...

[Sallyann1234]

This is just the same as GPS but with a different reference source, surely?
There's very little information given, but my understanding is that this would be a primary rather than a secondary system, i.e. not relying on anything in the aircraft.
As someone with considerable experience in this area, I can see all sorts of potential problems. It seems that the proposal relies on time differences for reflection of signals from multiple TV sites. I'm assuming that they would be looking at the TV signal carriers rather than the modulation on them, but this is complex matter with the current COFDM signals (8,000 carriers per multiplex)..
And each TV channel is used many times over across the country. Re-use of each channel is planned to minimise co-channel interference to domestic reception on the ground, but an aircraft will see and reflect signals from many transmitters on the same frequency. I'm not sure how the proposed system will sort them.

To deal with chevron's points:
1) the ITU would probably take little interest unless some modification was required to the TV transmissions, since the frequency planning criteria would not be affected. And if this was just a UK system, foreign broadcasts would not be needed.
2) and 3) yes absolutely.

I really believe for a whole host of reasons this is a non-starter.

[DaveReidUK]

There's a more detailed account of the research project here:

Air Traffic Control Systems Could Ditch Radar And Release 5G Spectrum (http://www.techweekeurope.co.uk/news/5g-mobile-networks-air-traffic-control-107240)

which is worth a read.

Given that the participants in the research include both NATS and Roke, dismissing it as a crackpot idea may be a tad premature.

[ZOOKER]

landedoutagain,

Which TV? You have loads of 'em up there.
If it's the one in the lounge, then it's a W2 problem.
If it's the one in the canteen, (sorry staff restaurant), relax, enjoy the food, the sunsets* and the view of Arran*, - especially at breakfast time.

*You don't get these features at Swan-wick.

[malakajin]

Daddy which channel is LAM hold ? Depends on the transmitters error scheme honey

[2 sheds]

DaveReid

Thank you for the link!

2 s

[Sallyann1234]

I didn't - and wouldn't - call it a crackpot scheme, in theory it should work.

It will be very interesting to see the results of the study. But for the reasons stated above and others, I don't think it is going to happen as a practical proposition.

[On the beach]

Why do the words "Tenner Reef" keep popping into my head?