End of Radar for ATC?

[pulse1]

I see that I can now convert my computer to a virtual radar for the princely sum of £450. This will apparently display details of every aircraft with Mode S over a radius of up to 198 miles.

http://www.kinetic-avionics.co.uk/ (http://)

I believe that this system (or similar) is being discussed at NATS, so is it likely to replace conventional ATC radar which is expensive to install and maintain? Will it also power the argument for fitting Mode S to all aircraft?

Once Mode S becomes compulsory Big Brother, and anyone else with a computer and SBS, can watch and record the movements of every aircraft in their area, and provide evidence of any slight infringement of the rules e.g. slightly below 1500' over the edge of a built up area.

I think that I am glad I will probably be too old to fly by the time that starts to happen.

[Capt. Vilo]

I've seen the prototype working first hand on my friends laptop, and it is very impessive. We watched an A/C arriving at LAM and being vectored into EGLL with it's heights, speed and call sign.


Is this the future ???????

[Evil J]

I must admit to being slightly concerned by this kit, and who may get hold of it and for what purpose - hopefully some sort of legislation will be brought in (like the wirless and telegraphy act) to at least attempt to make sure it only gets used for bone fide tasks.

[Pierre Argh]

You're probably right, to an extent... at least one UK agenccy is looking at the potential, and there are working experiments elsewhere in the world (where it would be impractical /unfeasible locate radar aerials... or where coverage is severly limited i.e. mountainous regions)... IMHO I don't think this will drive the introduction of Mode S, but rather be a "benefit" of a system that is coming anyway... there are many other, probably more pressing justifications for S?

Will it totally replace radar... big question. I believe it is still not certain that all flying machines will have to carry a transponder... so all the time, in the UK, you have commercial flights in Class G there could be a strong justification for keeping a primary radar system... and then of course there's a defence arguement... a "radar" system that relies on transponders also relies on a will to comply... Think 9/11?

[Jerricho]

And how long till somebody thinks they see something "bad" on their screen in their bedroom which is a perfectly legal and safe situation and calls my friends at the Daily Mail trying to make some money on a story.

What do they say? "A little information is a dangerous thing"

(How long till somebody comes along here and starts waving a "If you have nothing to hide" banner?)

[cdb]

And even better...

Now when we get jokers coming on frequency and making random calls, they'll be able to see where a/c are and point them towards each other!

Or, imagine the NIMBY living under an approach track somewhere... every time he sees something about to come over his house...

"BAW123 AVOIDING ACTION turn right 30 degrees"!

[tubthumper]

Never mind that. Does this mean I'll be able to work from home?

[Jerricho]

Sure. Till the battery on your laptop craps itself (like mine has) :(

[bookworm]

I see that I can now convert my computer to a virtual radar for the princely sum of £450. This will apparently display details of every aircraft with Mode S over a radius of up to 198 miles.

I don't believe it does. Because it's passive, it can only track those aircraft that squitter their position information as part of an Enhanced Mode S set-up.

Elementary Mode S doesn't include this ADS-B functionality, and so to do away with the radar would require a further mandate for every aircraft to carry a reliable position determining device like GPS, and for the output of that to be available in the downlink. That's fine for modern glass aircraft, but I think it will be many years before all aircraft are so equipped.

[ferris]

That's fine for modern glass aircraft, but I think it will be many years before all aircraft are so equipped. Really? A GPS costs less than a tank of fuel.

[dublinpilot]

If someone managed to jam the gps signal, then things could turn sour.

[bookworm]

Really? A GPS costs less than a tank of fuel.

The sort of unit that the authorities would allow to be prmanently installed and connected to a Mode S transponder to downlink safety critical positional information would, I think, cost rather more than that. Compare, for example, the cost of a TSO-129A IFR-approved GPS receiver at about $4000+ installed and its let's-go-hiking little cousin at about $100.

We have an aircraft with a GNS430 GPS and recently installed the GTX330 Mode S transponder. As far as I'm aware, we were either unable or not permitted to allow the GTX330 to squitter the GPS position.

[BleriotXI]

As an enthousiast, I'd love to have something like this! I listen to EHAM R/T a lot, and having the "view" would make it complete. 450 Pounds is a lot of money though :ugh: I think it won't be any legislation that stops me from buying it... it will be my wife.

[ferris]

The sort of unit that the authorities would allow to be prmanently installed and connected to a Mode S transponder to downlink safety critical positional information would, I think, cost rather more than that That will be a function of factors not yet determined. The ADS-B fitout trial being contemplated in oz will be considerably cheaper than you quote- the tender is called for (1500 a/c), and I think you will be shocked at how low it comes out at.
Would you have thought sat phones, or even mobile phones, would be so cheap so short a time later, when the first few people got them?
It may be that the "lets-go-hiking" accuracy of +/- 50m is quite accurate enough for the purpose contemplated. How accurate do you think accelerometer-driven RNAV is?

[bookworm]

I'd be delighted if it did turn out to be cheaper -- I'm a great fan of ADS-B.

Would you have thought sat phones, or even mobile phones, would be so cheap so short a time later, when the first few people got them?

Sure. So now we have billions of mobile phones in the world, and they cost almost nothing. Meanwhile the good old VHF AM transceiver, a vastly simpler technology, still runs to 4-digit prices if you want a class 1 (approved) unit. TSO-129A GPSs have been around for 10 years, and the price really hasn't fallen much. The overall market is just not big enough to bring the prices down.

It may be that the "lets-go-hiking" accuracy of +/- 50m is quite accurate enough for the purpose contemplated.

It's not the accuracy, but the certification of reliability that is the costly issue. The costs of certification have to be recovered through the price of the units sold to the aviation market.

[MikeGranby]

"I must admit to being slightly concerned by this kit, and who may get hold of it and for what purpose - hopefully some sort of legislation will be brought in (like the wirless and telegraphy act) to at least attempt to make sure it only gets used for bone fide tasks."

Absolutely. Can't have the plebs getting hold of information gathered with their tax money, now, can we?

[PPRuNe Radar]

Tax money pays for Mode S transponder equippage does it ??

Where do I get my free set for my aircraft then ??

[SirToppamHat]

I know the market of the modern airlines is tight, but I can't really see that the major issue for them is the cost of Mode S installation on new ac. Given the power of the airlines with gov'ts various, it also seems unlikely that they will be forced into it any time soon. However, as Pierre Argh said earlier:
all the time, in the UK, you have commercial flights in Class G there could be a strong justification for keeping a primary radar system

The cost of such a system for the average weekend pilot might well be prohibitive, so that it would seem that these are the people who will need help changing over. Am I right in thinking that some countries are considering funding (are at least subsidizing) installation for the light ac fraternity (and sorority)? And what about gliders, balloons etc? These are difficult enough to detect with a good primary radar, so the idea that they now need Mode S is no more tennable than that they should carry Mode A/C Transponders at the moment.

STH

[ferris]

Am I right in thinking that some countries are considering funding (are at least subsidizing) installation for the light ac fraternity Yes. In oz, the govt (realising it has to be inclusive for it to work) is talking about using money saved on not replacing SSRs for an ADSB rollout. They still have to get past those in GA fighting them:hmm:

Bookworm.
The govt can have a lot of control over that price of certification. We won't have to wait long to see, anyway. Amazing how the companies can play the game, too. Sometimes they need their foot in the door in case the money-spinning applications appear later.

[Evil J]

The unit in question does not just use ADS-B type info, reading a write up on it in a GA mag this month, there is some sort of internet tie up and you can get position info on all squawking aeroplanes within line of sight of the aerial.

Another discussion point is that some GA type airfields have installed it to help their AFISO/Radio operators prevent collisions, ensure noise abatement is complied with etc...can open, worms everywhere - does that mean that non-ATCO, non radar trained Radio op/AFISO then has a duty of care to prevent collisions??? Discuss...its an absolute minefield

[bookworm]

The unit in question does not just use ADS-B type info, reading a write up on it in a GA mag this month, there is some sort of internet tie up and you can get position info on all squawking aeroplanes within line of sight of the aerial.

Would you like to explain how that works then? If I can get position info over the Internet, why would I need a radio receiver?

The govt can have a lot of control over that price of certification.

It certainly can Ferris. And if it subsidises ADS-B for GA in the UK, I'll eat my GTX330 :)

[Squadgy]

Another discussion point is that some GA type airfields have installed it to help their AFISO/Radio operators prevent collisions, ensure noise abatement is complied with etc...can open, worms everywhere - does that mean that non-ATCO, non radar trained Radio op/AFISO then has a duty of care to prevent collisions??? Discuss...its an absolute minefield

This month's Today's Pilot mag states that the original reason for this system being designed following a mid-air between a helicopter and a microlight near Elstree, ans that had the Air Traffic Controller (by which I think they mean FISO), at Elstree has the SBS1 system they could have prevented the collision.

This is wrong on two points :

1. The microlight (any maybe the helicopter), wouldn't have had Mode S at the time of the accident and therefore wouldn't have shown up on the kit.

2. FISOs aren't taught, and are probably too busy, to interpret this pseudo-radar data.

Which GA airfields have installed this kit? Unless SRG provide guidelines as to its use IMHO it could only be used to provide 'out of interest' information to staff and not to provide any method of enabling advice to be provided to pilots. Additionally the vast majority of GA aircraft are not presently ModeS equipped and therefore won't display on the system.

Interestingly it does say that the CAA have purchased units for their 'analysis'.

[Evil J]

OK, having re-read the article I may have mis-read it first time around. It states :

"The system provides a "picture" of all aircraft fitted with a mode S/ADS-B(Automatic Dependent Surveillance Broadcast) SSR transponder system within a line of site distance..."

First time around I read that to mean either Mode S/ADS-B OR traditional SSR, but on re-read I think it may just be the way they've phrased it by calling ADS-B a form of SSR.

Like I said I have had no contact with these units and am going on what I've read.

Squadgy,

I agree whole heartedly but I'm quite sure that a fast talking, pumped up switched on lawyer would try and argue that if you had info in front of you that could have prevented a collision you have a duty of care to do something, whether required by law or not- not similiar to the many debates held on this forum regarding traffic info whilst under Flight Infromation.

[Pierre Argh]

The problem with unreliable position information can, I believe, be resolved by placing a network of Mode S receivers on the ground... the signal received from aircraft can be cross-checked (bit like DF auto-triangulation?), and in the event of error the aircraft's navigation equipment can be updated... i.e. no cost GPS?

Think back to the days when radar was obliterated everytime a rain shower loomed over the horizon, and SSR was subject to back and side lobes.... this is just new capability. The technology is being developed and will no doubt improve before/ if it to become a stand-alone system in widespread use.

[bookworm]

"The system provides a "picture" of all aircraft fitted with a mode S/ADS-B(Automatic Dependent Surveillance Broadcast) SSR transponder system within a line of site distance..."

It's almost straight from the advertising blurb, which is cleverly worded.

Track Mode-S/ADS-B equipped aircraft in real time*
...
The Civil Aviation Authority (CAA) requires aircraft to be Mode S equipped for flights operating as General Air Traffic (GAT) in designated UK airspace from March 2005 and for all categories of flights in all other airspace from March 2008.


What it doesn't say is that it only tracks the ones that do ADS-B, and there's no requirement for that anytime soon.

Don't get me wrong -- I'm not knocking the kit. I'm sure it's a super little innovation. But I think one has to be realistic about its capabilities.

The problem with unreliable position information can, I believe, be resolved by placing a network of Mode S receivers on the ground... the signal received from aircraft can be cross-checked (bit like DF auto-triangulation?), and in the event of error the aircraft's navigation equipment can be updated... i.e. no cost GPS?

Not sure you need a network. Mode S ground stations are designed to track the position of Mode S transponders using azimuth and range, just like any other radar. It's only when you take away the directional capability that they need the position sent to them.

[av8boy]

ADS-B/multilateration is working well for the approach at Innsbruck, is it not? I think it's a technology that holds great promise. However, at least on this side of the pond, I don't think there's much threat of it replacing primary radar. Our ARSR-4s are part of our Joint Surveillance System and, as such, are air defense assets. Sept 11 reminded everyone that we still need to be able to track primary targets (something ATC knew all along) and the plan to scrap the old ARSRs in lieu of SSR-only sites was abandoned. Depending upon the ADS-B model without primary radar just takes us farther down that road. So, I see a great deal of utility in the use of ADS-B in a radar-like setting as an additional tool, but to put all of our eggs in that basket is just foolish.

RE: GPS jamming... ALL ATC technologies are susceptible to interference and the trick is to recognize when somebody has mucked with the hardware. So we augment (for instance, through things like a Ground Based Augmentation System) and watch closely for signs that something has gone wrong. When it doesn't look right we stop using it and move to another system (you do it in the airframe and we do it on the ground all the time). So, yes, if somebody DID jam the GPS signal things would go "sour," but if you mean that aircrews would continue to fly a Cat III GPS approach (sounds fun!) after the jamming began, I disagree.

Dave

[Tacan400]

Coming to your part of the world! Not the end of radar but the winding back of it to merely a backbone system.

ADS-B will save the FAA $4billion over the next 35 years, for an investment in 'mobile NAS facilities' in every aircraft cockpit costing a total of $2billion.

They are looking at replacing 709 radar across continental USA with 566 ADS-B base stations and keeping only 161 radar.

General aviation fitment will cost between US$5,000 and $12,000, depending on the aircraft type and the upgrade route.

The FAA is looking at heavily subsidising their aircraft fleet and mandating aircraft fitment.

Australia is considering exactly the same approach.

Ground-based aircraft tracking stations are already a reality, ADS-B tracking systems don't worsen the risk.

ADS-B opens up a world of safety and operational applications to pilots, not just for ATC surveillance.

[Iron City]

TACAN400: You must have been reading the investment analysis fairy tales cooked up by the ADS-B program office and the vendors. When avionics were bought a few years ago for the Alaska Capstone operation in lots of 100 and 200 the cost of the avionics alone was more than your quoted total cost and then they needed to be installed. It cost the earth for the first time in a given aircraft mark/mod (how about 20K?) but once the design had been worked out and the STC issued it came down to 6-10K dollars per aircraft.

Nobody is doing away with primary radar and current VOR/DME if they already have it (they don't in parts of Alaska or Oz which makes ADS-B attractive). If it involves changing from a known and proved installed technology (like VOR/DME and primary radar and xponders) then it is a transition and they are HE!!.

Don't tell anyone but the picture on the scope with it's maps and data blocks and such is totally computer created and is not linked physically in any way to a primary radar. In fact, the only reason for the transponder (why did somebody name it secondary radar, it has nothing to do with radar) and the primary radar to have anything to do with each other is so the transponder ground antenna can spin around. If it does so pointing the same direction as the primary it makes it easier for the computer to produce the track file of beacon targets reinforced by primary targets and take the ghosts, angels, stationary, and other junk out and dump it on the floor.

The next cool radar thing is the integrated tracker that takes the output of multiple radars (primary or beacon) and puts them together and produces a data stream to make it easy to display a "radar" picture of any area of airspace you like without needing to know which facility the data came from or pulling your hair out to mosaic outputs from different sensors with custon software.

The inherent problem with ADS-B is the "D" part, it is dependent on the aircraft knowing where it is and telling everybody or somebody (ADS-A and ADS-C). Until that navigation is fairly bullet proof,as well as the communications, it will not likely be relied on in terminal or approach airspace. In oceanic or similar, sure, why not, it is the same functionally as a position report and there is no radar or ground transponder coverage out there anyway.

[bookworm]

The inherent problem with ADS-B is the "D" part, it is dependent on the aircraft knowing where it is and telling everybody or somebody (ADS-A and ADS-C). Until that navigation is fairly bullet proof,as well as the communications, it will not likely be relied on in terminal or approach airspace.

Like the "bullet proof" encoder altitude that ATC has been reliant on for decades, you mean? ;)

[HEATHROW DIRECTOR]

<<Like the "bullet proof" encoder altitude that ATC has been reliant on for decades, you mean? >>

Tell me more..........??

[Pierre Argh]

SSR has nothing to do with RADAR?... differing systems yes, one much more complex than the other... yes.

But, remember what RADAR is an acronymn for (Radio Aid to Detecection And Ranging) and I think you'll agree that is one of the basic purposes of SSR too?

[RevStar]

A few comments on this thread- hope it helps those who are interested in this subject:

The technology

1. ADS-B (over 1090 Extended Squitter) will give you the same set of data as Mode S Enhanced Surveillance (this version of Mode S having a mandate in UK, France and Germany). It is from the same on-board data register. The difference comes in position determination - ADS-B uses aircraft positioning sources, Mode S uses azimuth and signal ranging from the ground.

2. The SBS-1 unit from Kinetic will not interrogate aircraft. It is merely a receiver. However, within this limit, it can receive whatever data is sent by the aircraft. This may be Mode S information (no position!) or ADS-B 1090ES information (with position). So technically, they can talk about Mode S reception - it's just that (to my mind) it can't be used by them for anything.

3. Another technology which uses the 'opportunity' signals from Mode S (and anything else on the 1090MHz frequency) is multilateration. This is what Innsbruck have implemented successfully, ostensibly as a support to RNP 0.3 operations.

4. The Dependent nature of ADS-B is indeed an issue (i.e. dependent on where the aircraft thinks it is). Not so much from an accuracy point of view - the figures can be astounding. The main issue (amongst others!) comes from the integrity of GPS, as it currently stands. GLONASS is not operational - only 11 of the necessary 18 satellites are up there. India may launch 3 more GLONASS sats to kick-start its own space programme, but that still leaves us 4 short. How will this therefore be solved? Initially, ADS-B will only be used in low density areas, where procedural control is a viable back-up. Another mitigation is using independent position validation via multilateration (triangulating the aircraft signals to obtain a position estimate).
As we get WAAS, EGNOS, GPS Phase 2, Galileo, MTSAT, China's SBAS etc, I believe the integrity will reach levels we can accept for safety-of-life services such as aviation.
All this is assuming the ADS-B position is purely coming from GNSS... actually, it is likely to become an FMS output, and will be compatible with the airspace requirements (e.g. using DME/DME, INS/IRS etc).

5. For security reasons (and safety mitigation reasons), I don't believe ADS-B will ever replace Primary Radar. Not least because the military own a load of systems and will keep them for air defence purposes.


The implementation plans

Fact: Mode S SSRs are expensive. Multilateration (MLAT) and ADS-B ground stations - often combined - are cheaper. And easier to maintain. And can extract potentially more information at a higher update rate with greater accuracies.

Australia has purchased 1090MHz ADS-B ground stations, and will carry out radar-like en-route services using ADS_B sole means surveillance. Indeed, ICAO, Eurocontrol, the FAA and Airservices Australia have almost agreed on a safety and performance case for ADS-B (comparative to radar), such that it can be used in place of radar.

As TACAN mentions, the USA is currently considering a potential mandate for ADS-B operations, so that they can reduce their infrastructure. This is because they MUST become cost-effective. It isn't an option any more. Under the plans going to FAA top-brass (and congress), as radars require replacing (over time), they would be rationalised and phased out in place of ADS-B.

Europe is starting to consider a similar route. Again, cost pressures (cost transparency) for the ANSPs is the main issue. A secondary issue is the potential to have Gate-to-Gate surveillance (a surveillance layer covering a Single European Sky!). Wide Area Multilateration with ADS-B data is the possible future direction for surveillance.

Iron City: investment analysis fairy tales? - maybe? But I believe in the next 10 years, that frog will have turned into a prince.

[BDiONU]

Yes Australia is involved in a large trial of ADS-B but its NOT a radar replacement. Its going to replace their procedural service, so there is no correlation between radar and ADS-B in the Australian model.

I think the biggest 'problem' with ADS-B (and I really like the concept from an ATSP perspective) is that it would require a mandate for every aircraft to be equipped. That gives an issue for the GA fraternity but more than that is the probability that the military will fight it very hard. They're already exempt from RVSM regulations and ADS-B gives a lot more data!

BD

[M609]

I'm reluctant to give up 'my' trusty old radar at present time........ ;)

A spotter friend of mine has gone and bought this lot, and alerted me to this forum topic.

This Mode S decoder connected to Google Earth 3D display, in real time!

http://www.kineticavionics.co.uk/forums/viewtopic.php?t=447

Now it's just for the tec boffins to make some 3D display for us!!!!!!!! :\