MLAT trial at Dundee

[piperboy84]

I see they are rolling out some new technologies to track aircraft in a non radar envoroment. Is anyone familiar with this equipment?

https://www.worldatmcongress.org/Uploads/2017%20Presentations/Electronic%20Conspicuity.pdf

[27/09]

Yep, there's quite significant deployment of MLAT in the "Land of the Long White Cloud ".

It's cheap way for the local ANSP ( I think it's called NATS in your part of the world) to provide surveillance , no more expensive radar heads. Along with ADSB it effectively shifts a lot of the costs of radar surveillance onto the aircraft owner.

[piperboy84]

Yep, there's quite significant deployment of MLAT in the "Land of the Long White Cloud ".

It's cheap way for the local ANSP ( I think it's called NATS in your part of the world) to provide surveillance , no more expensive radar heads. Along with ADSB it effectively shifts a lot of the costs of radar surveillance onto the aircraft owner.

But if I’m understanding it correctly it requires multiple off airport hardware units for monitoring in the airport vicinity which would incur costs to landlords for siting, utilities to power and connect the units if none exist and on going maintenance, similar to marker beacons which can incur significant costs.

[27/09]

I'm sorry I don't know the detail. I do know MLAT is providing coverage where traditional surveillance I.e radar cannot do so effectively and it's replacing radar because of cost advantages.

I suspect the sites are solar powered or are co located with other services that already have power on site. The MLAT sites also have a small footprint.

They are just a receiver with a small aerial with low power requirements. I don't know what the density requirements are but figure there are probably more cell phone towers per square area on average.

[27/09]

Have a look here. Wide Area Multilateration (http://www.multilateration.com/applications/wide-area.html)

This is just one page on that site, have a look around on there and I think it will answer your questions.

[dont overfil]

Have a look here. Wide Area Multilateration (http://www.multilateration.com/applications/wide-area.html)

This is just one page on that site, have a look around on there and I think it will answer your questions.
Hi Piperboy,
Strongly recommend that you come to the meeting at Perth on 21st.
There are six receivers in the local area including one at Perth. Come up to the tower and see the display. Uavionix are making a very generous offer to try to make the area 100 per cent known traffic.
Sorry, that was meant to be your quote Pb.

[Chuck Glider]

From piperboy's linkUncontrolled Airspace
FAS has to (my bold) find new methods to enable diverse operations and growing traffic numbers to continue to safely integrate in uncontrolled airspace
Has to? It's uncontrolled airspace FFS!

[tescoapp]

There is no way in hell this will create a known traffic environment.

It requires everything to have a mode S transponder and for it to be turned on.

And as most of he problem traffic in the area won't use a radio apart from the microlight chat frequency your on plums.

[LEGAL TENDER]

Edinburgh Approach uses Wide Area MLAT

[CloudHound]

Has a date for the start of the trial been set?

[airpolice]

360radar.co.uk is an independent system for enthusiasts which is available to all for £20 a year. Free if you contribute data. The cost of contributing is about £100 for the hardware, and you need to have an internet connection.

One advantage of contributing is that you get your own local display.

Unlike FR24, this system will show you almost all ADSB traffic out there, including QRA, Tankers, Power FLARM and private jets. The big exceptions (for now) are F22 & F35.

Where aircraft are sending ModeS returns with position info, only one hit is required, but for calculating the position of an aircraft not sending gps co-ords, the system needs five receivers to see the transponder returns to workout where the aircraft is.

This is never going to work for Mode a/c only aircraft, as the older transponders all look the same, but ADSB / Mode S boxes are uniquely identified.

[dont overfil]

There is no way in hell this will create a known traffic environment.

It requires everything to have a mode S transponder and for it to be turned on.

And as most of he problem traffic in the area won't use a radio apart from the microlight chat frequency your on plums.

If you have a working transponder it is now a legal requirement to have it switched on.

There are steps in place to equip most of the locally based aircraft that are not already equipped. The critical area is not massive and the locals are being briefed.

Cloudhound,
Trial starts officially 22nd December.

[tescoapp]

So are the microlights getting mode S?

[Jan Olieslagers]

Why not? Mine has been so equipped in early 2017. And in Germany, for one example, the majority are.

[tescoapp]

There is zero reason why not...... And zero reason not to turn them on either.

Just as there is zero reason not to carry a radio or use it on a frequency that other airspace user are using.

Doesn't mean that they will do it.

[dont overfil]

It is in everyone interest to make this trial work to hold back the proliferation of controlled airspace.

All the Dundee and Leuchars based aircraft are equipped with either ADSB, Flarm or mode S and steps are underway to have the Perth based aircraft similarly equipped.

Leuchars and Scottish Tay sector control IFR arrivals and departures and there are letters of agreement between all parties. There is a determination to make this work in what is a busy training and recreational area.

[Jan Olieslagers]

@Tescoapp: zero reason? Except the limited availability of sponsors? I spent 2500+ € on 8,33 + mode-S but not everybody can. Are you going to ban them from the skies?

[dont overfil]

So are the microlights getting mode S?

A few already have mode S. The other regular flyers are getting Sky Echo which is a key part of the trial.

[tescoapp]

No banning just pointing out that trying to make that bit of airspace known traffic is going to be very unlikely.

As its class G and by rights you don't need a radio never mind a transponder to be in it

[dont overfil]

It's just a trial at this stage, but if the results are satisfactory it may prevent the need for a TMZ or RMZ. Hopefully the LOA's will fill the gaps. Remember this is not for control. It's for awareness. From what I've seen so far it is excellent.

[Jan Olieslagers]

it may prevent the need for a TMZ or RMZ

That's not up to logic. I agree with @tescoapp so far: if this MLAT stuff is to work, every plane needs to carry an active transponder (though I don't understand from the given text it needs to be mode S, but that's a side-point). So a TMZ would in fact be required to make it really waterproof. Otherwise, it will never offer more than suggestions.

[dont overfil]

That's not up to logic. I agree with @tescoapp so far: if this MLAT stuff is to work, every plane needs to carry an active transponder (though I don't understand from the given text it needs to be mode S, but that's a side-point). So a TMZ would in fact be required to make it really waterproof. Otherwise, it will never offer more than suggestions.

This test does not require a transponder. It can be a much less expensive Sky Echo, Flarm or perhaps others. The test equipment is supplied by Uavionix, the suppliers of Sky Echo.

Sky Echo is ADSB so needs only to be picked up by one receiver unlike mode S which requires 3 for multilateration.

[Jan Olieslagers]

But @tescoapp commented on MLAT as such, not on the present experiment.

(and don't get me started on the illusions of Flarm, there's been more than enough threads about that)

[Crash one]

If you have a working transponder it is now a legal requirement to have it switched on.

There are steps in place to equip most of the locally based aircraft that are not already equipped. The critical area is not massive and the locals are being briefed.

Cloudhound,
Trial starts officially 22nd December.

I must be a cynical old git.
Electronic conspicuity is a most excellent thing, yes.
But! Until every flavour of every device can see and be seen by every other flavour from commercial, military, bug smashers, gliders, microlights etc then these trials are, in my miserable opinion, no use to a large number of pilots.
Yes it will probably show all ADSB/mode S equipped aircraft to ATC or each other.
Will it reduce the number of mid airs? How many mid airs are there per month so we can gauge how successful this stuff is? Or is it like this can of Elephant repellent that I spray in my kitchen? It must work very well, I haven't seen an Elephant in here for years.
I don't have a transponder of any kind, I don't have room nor the price of one.
I will use a PAW unit,,,,only,,,,.
What gets up my nose is the number of radio frequencies that it is legal to be transmitting on in the same few square miles. "The microlight freq",,,"The glider freq",,,, "Parachute freq",,, Scottish, Perth, Fife, Leuchars, Safetycom, Dundee, Edinburgh, etc.
Can I have an "Emeraude freq" and talk to myself?
Rant mode to standby.

[Duchess_Driver]

Creating awareness of other traffic, perhaps.

It saddens me that we are all focussed on other aircraft being the only possible threat out there. Just hours after the dreadful events of Waddesdon last month, a EMS chopper in the US crashed apparently due birds. What are you planning to do about them? Ring them with transponders? Then what about CFIT - let’s put transponders on all the mountains... then what about weather and windshear? What about obstacles on the apron? transponders for baggage carts? We’re driving towards so many alarms and bells and whistles in the cockpit that we will become immune to them or, just turn the annoying things off anyway.

Somewhere we need to stop and take stock of what is happening, not just in our hobby/profession but in our lives. We’re continually driving technology to put in place a less risky environment but at some points the costs outweigh the benefits. There will come a time when we need to ‘person up’ and accept that there is risk in what we have chosen to do. We either accept that risk and carry on or pack up and poke off.

[piperboy84]

In my aircraft I have 5 possible methods of picking up other traffic. 1: My Garmin 430 showing TIS info from the TXP which obviously doesn't work in the U.K. 2: A Xaon PCAS, which is pretty good but is limited to other aircraft being painted by radar and my unit then piggybacks on their transponder response to get a location fix, but the maker is now out of business and the unit is not supported. 3: My Garmin 660 panel mounted VFR gps displaying info being bluetoothed from the GDL 39 ADSB IN receiver of aircraft that are equipped with ADSB OUT via air to air. My IPAD displaying the same ADSB IN info sourced from the GDL 39 and presented in the Garmin Pilot app. 5: Flightradar24 on my IPhone or IPad via 4g connection, I have no idea how this one works but I assume there are some magic pixies that make it happen.

As you can see this is what the Yanks refer to as a clusterf&$k. Some don't work at all in the U.K. others work in a radar environment, others in a ADSB equipped setup. And if I want to go ADSB OUT I'd have to pay Garmin a pile of dough to get my 430 upgraded for WAAS and the transponder equipped for ES.

So if the equipment in this trial has the ability in terminal environments and coverage for procedural routes in uncontrolled airspace to identify aircraft with Mode A,C&S txps & ADSB equipped and present them all together on one screen AND provide me with a WASS receiver and ADSB OUT capability in a small glare shield mounted unit for a reasonable price I think they are onto a winner.

As for folk who don't have a transponder or have one and won't turn it on, I think they are being selfish especially with the cheap base model units that are available today.(sorry in advance Trev).

Edit to add: If you look at the new RNAV (GNSS) approaches for Dundee the 'missed' puts them out over the hills to the north at 3000ft (and potentially out of sight of Leuchars radar) , if I was a CAT pilot with a load of pax flying the missed for 27 my rear would be puckered up tighter than a badgers knowing there could be some VFR bimbling dip**** coming down the Strathmore Valley the opposite way at the same altitude in his Maule checking his Facebook messages, or worse flying along IMC not on a clearance.

[Crash one]

No offence took Dunc.
I think this conspicuity thing needs to be put into perspective.
If you regularly fly down Mig alleys, then yes it needs serious kit and consideration.
If you spend your time bimbling around deserted hills up here in the frozen norf, then where's the problem? Except, do the military squirt ADSB mode S?
Compare the number of mid airs to the number of CFIT, engine failures over mountains, inadvertent IMC etc. We need a different form of high tech to avoid those.
Gadget fiddling could well be part of the problem.

[dont overfil]

The CAA have stated that they consider ADSB is the way ahead. If Sky Echo behaves in this test as promised it must be the answer at £600.

I am situated 12 miles from Dundee with hills over 1000ft in between. I can see aircraft with ADSB on the ground here and at Dundee Airport. The Leuchars Grobs use Flarm and currently mode S as well. Some mode S returns (MLAT) I can see from about 1500ft upwards which is at least as good if not better than radar in the area. This is being achieved with one less receiver than is ideal. I genuinely believe we are close to the "VHS or Betamax" decision time.

tescoapp, I don't think there are any parallels here with the Beechcraft accident. The AAIB report left more questions than answers!!!!

There is no need for anyone here to feel inadequete.;) Very few of the scheduled aircraft that fly to Dundee have ADSB.

[Itsatrickgetanaxe]

Tesco, I think you may be being a bit pessimistic re take up of mode s and indeed adsb amongst microlights, I have been pushing out adsb since I was allowed to connect up my uncertified GPS.

In fact at my base the microlight with adsb out and in capability outnumber the Larger aircraft fitted thus by 3 to 0

[Forfoxake]

Anyone who has flown a reasonable number of hours, even in relatively quiet airspace in Scotland, knows that "See and avoid" is not very effective due to the limitations of the eyes. So electronic conspicuity is a great thing and I have flown with a transponder (Mode C, swithed on) for ages and, a few years ago, adopted PowerFLARM to help reduce the risk of collision. Nevertheless, I think that ADS-B in/out is the way forward, especially if it becomes cheap enough to fit to everything in the air, including drones but excluding the birds!

However, the main point of such a system has to be collision avoidance imho. Virtual radar is very interesting and entertaining but, as a pilot, I really only want to know about the ones that might hit me! Ultimately, the point of ATC is collision avoidance but an ATSU also often has to maintain certain minimum legal separations so it's interests are not necessarily the same as the individual pilot's.

So I think now is the time to grasp the nettle and develop a cheap and effective collision avoidance system (probably based on ADS-B) with built in collision avoidance algorithms (similar to FLARM) and clear audible warnings of high collision risk. Mid-air collisions are thankfully rare because the air is so big but they are almost invariably terminal. It is now within our power to reduce the risk dramatically so let's get on with it!

[airwave45]

I really don't give a rats left testicle which system it is, but our lords and masters in the UK have indicated ADS B it is.
Have been ADS B in in the glider for over a year, when the boys in Edinburgh get the cert for their doobrie, I'll be ADS B out too.
Current flight instrumentation in gliders means you can gleefully run FLARM and ABSB from the same display, some of which take the ADS B in signal and run a TCAS algorithm on it (Flarm already does it)

See and avoid is next to useless, I have the hours and the experience in busy traffic environments to state this as a fact rather than an opinion.
Glider gaggle flying, see and avoid is the only way (and even then we get multiple mid airs in that environment, but it's a competition environment and acceptable as such)

For general bimbling about, fit and use ADS B.
Stop bleating about the cost. you fly.
Fit modern batteries if power is an issue.

Any avionics system can be depreciated over 7 years, you'll be 40 quid a month that way to have ADS B in/out, whats that, 20 mins flight time ?

[airpolice]

Very few of the scheduled aircraft that fly to Dundee have ADSB.

That can't be right.

[piperboy84]

That can't be right.

It is, I fly around, over and into Dundee all the time and nary a peep on my ADSB IN box.

[NorthSouth]

It's just a trial at this stage, but if the results are satisfactory it may prevent the need for a TMZ or RMZ. Hopefully the LOA's will fill the gaps. Remember this is not for control. It's for awareness. From what I've seen so far it is excellent.
I'd be amazed if anyone attempted to impose a TMZ or RMZ in this area. Reading between the lines, does the suggestion of a TMZ imply that the notion is that Dundee would be the controlling authority, and since they don't have and are unlikely ever to get primary radar, they could only control using some form of SSR, i.e. in this case MLAT, and that would mean they'd have to have a TMZ.
But that would beg the big questions of (a) Dundee ATC's Area of Operational Responsibility and (b) what Leuchars would then do in the area.
Any proposals for SSR-only, or even mandatory radio, in this area will have to grasp the nettle of the significant numbers of gliders from Portmoak that will want to continue to exercise their rights to operate without transponder and/or radio.
Looking at the history of airproxes in this area, there have been around 30 since 2001. The vast majority were Cat.C (no risk of collision). There were three Cat As, all of them occurring within an ATZ where the use of radar information to separate traffic is more problematic.
So the MLAT trial may well provide some valuable lessons. But I'm not so sure those are lessons that have direct applicability in *this* area.
NS

[NorthSouth]

Very few of the scheduled aircraft that fly to Dundee have ADSB.That's probably of more significance in terms of the "Very few...scheduled aircraft that fly to Dundee" rather than what kit they carry (or don't). Is this whole thing driven by Flybe's withdrawal from Dundee and HIAL's desire to get more commercial operators into Dundee?

[dont overfil]

That's probably of more significance in terms of the "Very few...scheduled aircraft that fly to Dundee" rather than what kit they carry (or don't). Is this whole thing driven by Flybe's withdrawal from Dundee and HIAL's desire to get more commercial operators into Dundee?

I believe this is part of a nationwide test of the technology. It could also be a nice little earner for the contractor eventually.

The question of Dundee's area of responsibility is a good one. They have a 2nm ATZ but have three instrument approaches out as far as 15 miles and offer a procedural service only. It's only one example of the fuzzy nature of the regulations. However this test, if it works, will allow the Dundee controllers to see most of the traffic and "suggest":rolleyes: to their procedural traffic where to look.

The glider traffic is generally well behaved and stay well clear of the ATZ's in the area and will usually call if they are anywhere near.

[NorthSouth]

Back in the good old days of 2008 when ATSOCAS were being re-designed, one of the main issues was a concern to stop controllers offering what seemed like a radar service to traffic on a FIS, so that (mainly GA) pilots weren't lulled into thinking that someone else was doing the lookout for them.

Personally I don't think the reformulation into BS has done one iota to resolve that problem. I don't blame controllers for this - the ones that give you traffic info based on what they see on their radar are only trying to help. But it does reinforce the impression given to often inexperienced pilots that if there's a conflict out there, the controller will tell them about it.

Now, with this trial, we have the prospects of procedural controllers at Dundee (will they have to be re-trained as radar controllers?) using an ATM to "suggest" to pilots where they might look for conflicts. Again, I can see the good intentions behind this, but because it's still not a radar service, and it's in Class G, it could really muddy the waters about who's responsible for collision avoidance. I expect the CAA will look at that aspect very closely.

I also wonder how the Dundee controller (and I don't imply any criticism here) will cope with monitoring an ATM as well as looking out of the VCR to visually monitor traffic positions on the ground as well as in the air. Potential further dividing of attention.

Personally I reckon they should move the Leuchars radars to a spot that can better monitor the Dundee as well as Leuchars approaches, then move the Leuchars controllers to a new radar room at Dundee where they can do a proper Dundee Approach function as well as Leuchars App and LARS. HIAL could then charge them lots of rent for being there 24/7 in the off-chance that a Typhoon might want to divert to Leuchars. :)

[dont overfil]

NorthSouth,

Too sensible. I don't think the MOD have any budget left after spending millions on the cadet acommodation, (air-con included:rolleyes:), at Kirknewton.

However, as I said earlier, this is part of a wider test looking further ahead probably to eventually replace radar. That would require a shake up of the rules as they are now.

The early test stage of catering for autonomous aerial vehicles? The FAA are making ADSB mandatory from 2020.

[Chuck Glider]

The FAA are making ADSB mandatory from 2020.
With exemptions, I believe.

[Chuck Glider]

I'd be amazed if anyone attempted to impose a TMZ or RMZ in this area... (Dundee)
Keep in mind that it's HIAL that operate Dundee. They'd be up for it.

[airpolice]

Very few of the scheduled aircraft that fly to Dundee have ADSB.


Am I missing something here?

According to the HIAL website, the only scheduled service operating into Dundee is the Loganair from Stansted.

So, very few of that fleet have ADSB.... Really? Stansted and back on Mode C or limited Mode S only?

How many non ADSB airframes do Loganair operate out of Dundee? If very few of them have ADSB, are they planning to change that any time soon?

[good egg]

The FAA are making ADSB mandatory from 2020.

How's the EASA mandate going?

[dont overfil]

Am I missing something here?

According to the HIAL website, the only scheduled service operating into Dundee is the Loganair from Stansted.

So, very few of that fleet have ADSB.... Really? Stansted and back on Mode C or limited Mode S only?

How many non ADSB airframes do Loganair operate out of Dundee? If very few of them have ADSB, are they planning to change that any time soon?

The Saab 340's don't have it, nor are they equipped for the GNSS approach. I heard 2020 mentioned a couple of years ago but I think their days are numbered. Don't know about the 2000's. I may have seen one of the leased ATR's with ADSB.

[NorthSouth]

The Saab 340's don't have it, nor are they equipped for the GNSS approach:confused: really? So what are all those GNSS approaches at the HIAL airfields for?

[piperboy84]

:confused: really? So what are all those GNSS approaches at the HIAL airfields for?

Me!! For keeping my IR currency 👍

[dont overfil]

:confused: really? So what are all those GNSS approaches at the HIAL airfields for?

I think the Twotters will be equipped. Other users are GAMA with the air ambulance and the guy with the PC12 on Islay.:cool:

Edited to add: Maybe Piperboy as well. :-) He's desperate for some traffic to use his gadgets.

[BossEyed]

The FAA are making ADSB mandatory from 2020.

Not universally, though: Class B & C, generally where there is a "Mode C veil" now and Class E above 10,000 ft less where at 2500ft or below above the surface, and the Gul of Mexico. See CFR91.225 (https://www.ecfr.gov/cgi-bin/text-idx?node=14:2.0.1.3.10#se14.2.91_1225).

[dont overfil]

Not universally, though: Class B & C, generally where there is a "Mode C veil" now and Class E above 10,000 ft less where at 2500ft or below above the surface, and the Gul of Mexico. See CFR91.225 (https://www.ecfr.gov/cgi-bin/text-idx?node=14:2.0.1.3.10#se14.2.91_1225).

Yer..But.. What else have the Romans done for us?:)

[DB6]

The approach lights on 27? And the aqueduct.

[piperboy84]

Well attended and informative MLAT presentation last night given by Dundee Tower boss. Quote of the evening goes to DH-H responding to a discussion on ways to keep non transponder aircraft out of CAS
“The only way to guarantee non infringement is with a Bofors”

[piperboy84]

New MLAT boxes dished out today at Perth to start the trial. Skies busy as hell with everybody flying round in circles with eyes glued to the box!

[dont overfil]

New MLAT boxes dished out today at Perth to start the trial. Skies busy as hell with everybody flying round in circles with eyes glued to the box!
Two receivers off line at the moment due to power outages so mlat (mode s) traffic not showing.
Hopefully up and running again by 27th.

[piperboy84]

Two receivers off line at the moment due to power outages so mlat (mode s) traffic not showing.
Hopefully up and running again by 27th.

Not really grasping this technology, I took Tim for a test flight today and I did not see anybody on my Air to Air ADSB IN equipped Garmin GPS bluetoothed to a Garmin GDL 39. Upon landing the guys in the club said they seen all the new devices that were flying on FlightRadar. Do these new units only transmit info to the ground stations but not to other airborne ADSB In receivers?

[dont overfil]

Not really grasping this technology, I took Tim for a test flight today and I did not see anybody on my Air to Air ADSB IN equipped Garmin GPS bluetoothed to a Garmin GDL 39. Upon landing the guys in the club said they seen all the new devices that were flying on FlightRadar. Do these new units only transmit info to the ground stations but not to other airborne ADSB In receivers?
The others could see each other with one exception. I did not see an ADSB signal from your aircraft.

[bern444]

I don't know anything about official MLAT tests. but Flightradar24 and the other similar systems use data from large numbers of amateurs around the world.

At LTFC at Fairoaks one of the members, whose aircraft only has Mode S and not ADSB, was complaining that he can't see his aircraft on FR24 (when someone else is using it) until it's quite high up.

We've put in a 1090 receiver at the clubhouse - our simple system consists of a Raspberry Pi, a cheap DVB ADSB dongle and an £18 aerial. It contributes to MLAT calculations as well as sending position info, currently to just FR24. Sadly it turns out that you need four receivers in line of sight to do MLAT, so my colleague's aircraft will stay invisible at low level until other locals join in

Bernie

[airpolice]

I don't know anything about official MLAT tests. but Flightradar24 and the other similar systems use data from large numbers of amateurs around the world.

At LTFC at Fairoaks one of the members, whose aircraft only has Mode S and not ADSB, was complaining that he can't see his aircraft on FR24 (when someone else is using it) until it's quite high up.

We've put in a 1090 receiver at the clubhouse - our simple system consists of a Raspberry Pi, a cheap DVB ADSB dongle and an £18 aerial. It contributes to MLAT calculations as well as sending position info, currently to just FR24. Sadly it turns out that you need four receivers in line of sight to do MLAT, so my colleague's aircraft will stay invisible at low level until other locals join in

Bernie

There is an alternative network, 360radar.co.uk which in some ways is better than FlightRadar24. For less than £100 per station, I'm sure an active club could find four members and a clubhouse, all a couple of miles apart, to host a receiver each.

[bern444]

I can't see what we gain. FR24 give us a free business subscription because we supply data, and is free to use. Not sure what use the subscription is, but that's not why we put it there.

I'm entirely open to suggestions, as we only just got this going, but it has to be worth doing.

B

[airpolice]

I can't see what we gain. FR24 give us a free business subscription because we supply data, and is free to use. Not sure what use the subscription is, but that's not why we put it there.

I'm entirely open to suggestions, as we only just got this going, but it has to be worth doing.

B

360Radar shows all of the traffic that it picks up, including Military, Coastguard, Air Ambulance etc. FR24 filters some of that out.

[bern444]

Ah - I see.

The local feed, of course, straight from the RPi, doesn't filter or delay anything. I haven't set it up to do so, but it could be seen by anyone if I fiddled with the router a bit. The input is line of sight, but we can see aircraft as far north as Cambridge and well out over the sea to the south.

Early days as yet, I'm not rushing to change anything, though I am encouraging locally based members to spend the cost of a quarter of an hour in the air to set up their own.

B

[threemiles]

It is not so easy with Mode-S and Multilateration in Dundee because there is no Mode-S interrogation in the airport vicinity. That's why ADS-B can be the future only.

[dont overfil]

It is not so easy with Mode-S and Multilateration in Dundee because there is no Mode-S interrogation in the airport vicinity. That's why ADS-B can be the future only.

There are 6 mode S receivers within 12 miles of Dundee as part of the trial.
I can now see mode S traffic in the Dundee circuit down 60ft. This of course is not connected with "Flight Radar 24" or any of the other commonly available surveillance systems.