Tassie gets Multilaterated!

[Spodman]

http://www.airservicesaustralia.com/media/press_releases/pr.asp?id=PR15_06Improved aircraft surveillance across Tasmania - 15/06

Airservices Australia has contracted air navigation technology firm Sensis Corporation to design and install equipment to provide safer and more precise aircraft tracking in Tasmanian skies.

Known as Wide Area Multilateration (WAM), the system will initially be compared to the present secondary radar system in Tasmania in order to obtain regulatory approval from the Civil Aviation Safety Authority (CASA) to use WAM for aircraft separation.

The system, being installed in 2007, will also be used to collect data to support the use of WAM as an alternative technology for precision monitoring of aircraft on final approach to Sydney Airport's parallel runways.

Airservices Chief Executive Officer, Greg Russell said the new system would improve coverage for air traffic controllers compared to that currently achieved with transportable radar and particularly at lower altitudes around Hobart.

'When commissioned in early 2008, the new system will provide complete coverage of mainland Tasmanian airspace and, when coupled with the radar-like aircraft tracking technology ADS-B, will cover a 250 nautical mile radius of Launceston and Hobart,' Mr Russell said.

Multilateration systems determine position through triangulation of data received from aircraft via a number of receiver stations on the basis of time difference.

Mr Russell said multilateration was more accurate than secondary radar.

'The Tasmanian system will provide position data with better than 150 metre accuracy and an update rate for air traffic controllers as fast as once a second,' he said. Guess it is official then! This will mean a radar-like service down to ground level at Launceston & Hobart with only mode C transponders in the aircraft!

[Capn Bloggs]

So what's the big deal about Tassie?

Why isn't this being installed in the Goldfields and Pilbara?

:ugh:

[Scurvy.D.Dog]

.. should be good if it works as advertised! ... does ADS-B also :E Greg Russell said the new system would improve coverage for air traffic controllers compared to that currently achieved with transportable radar …. :ooh: … maybe he is referring to TXPDR equipped aircraft … :oh:
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Bloggsie .... over 910,000 pax thru LT and 1.4mil thru HB last year.... that's the big deal!!
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Tassie is the trial area as the RADAR is there (for data comparison) with the view to removing the Transportable after MLAT commissioning!
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The Pilbara and Goldfields (and other areas such as YBAS) should have it also IMHO after it is proven!

[Buckshot]

So I guess this means from 2008 we'll no longer hear the phrase from Centre "at 30 DME contact tower, radar services terminated on transfer" even though the tower controllers already have radar...

[Capn Bloggs]

even though the tower controllers already have radar...

Tower controllers DON'T USE RADAR. They're visual only! That's the way it's done in the US, OK?! :E :}

[jumpuFOKKERjump]

"...radar services terminated on transfer"Tower controllers DON'T USE RADAR. They're visual only! That's the way it's done in the US...Yes, but the tower controllers at Melbourne/Essendon don't use radar either, but approach doesn't terminate the radar services on handoff to them. They don't in the US either, unless they have also left radar coverage. Until Oz Enroute ATC retain the responsibility for controlling IFR flights in the tower's airspace until they are cleared for approach you will keep hearing it. I say "identification terminated on transfer" to add some variety.Why isn't this being installed in the Goldfields and Pilbara?Airservices is still under a ministerial direction from NOV 2004 to provide a radar control service anywhere they replaced E airspace over D with C. This applies over Tassie. Presumably it will be implemented there, with commissioned WAAM as required equipment. If this farcical directive continues I expect WAAM will be installed at Albury, Tamworth, Coffs, Maroochy & all the other D towers. Then the goldfields. The current minister's new commitment to NAS may inject some reality into this process.

[MrApproach]

In Melbourne the radar service is not terminated it continues to ground level because Approach control "owns" the airspace. The Tower "owns" the runway so you call them to get an aerodrome control service. i.e. a landing clearance. In Launceston the Tower controller is also an approach controller (procedural) and the Tower "owns" the airspace, hence the radar service is terminated.

Multilat's advantage over ADS-B is that it works on the currently installed transponders. It doesn't require Airservices to buy everybody an ADS-B unit for their aircraft. It also does not suffer from inherent GPS inaccuracies, downside is it requires more units to perform the triangulation.

[Scurvy.D.Dog]

.. yes most procedural towers have a traffic display (TSAD) tis used for positional confirmation :} and provision of class D services. Tower/approach is not only visual though ... trouble maker Bloggsie to the principles office :E
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Dog don's stack hat :8
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.. why would you want separate radar approach when it can be done from the tower more efficiently :ooh: :p :E .. there is some work underway to improve the uses of Tower display systems .... question is, (in a visual sense particularly), is it less or more of a distraction for tower controllers to be searching for a target with bino's or a glance at the screen ... if we can use one and not the other why??? ... and yes I know the rules regarding screens in towers :rolleyes: ... it is a study that needs to be done A.S.A.P :ok:
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... damage done ... I'll get me coat :\

[rogerexplosion]

Beauty. Should make things a bit easier for the tower boys in Hobart with all the Cambridge and Tasair traffic flying so close to A320's and 737's.

Now.... if only they could just sort out the damn terminal works :bored:

[IMHFO]

OK I'll give the hint and you join the dots....

Scratch one PSR/MSSR at Launy and install one Multilat at Launy = only dependant systems get seen!!!!

[Roger Standby]

who wants to see the primaries, anyway? The real question is can ASA get it in before the radar in YSSY craps itself?

[peuce]

Just had a wild quick thought while reading these posts ...

1 x multilat + 1 x surface movement radar = remote tower control from centre ???

Daresay there's other considerations .....

[Buckshot]

Scary thought, Peuce. With the wx we've had in the last couple of days, let's hope that's not the plan. Yesterday a DJ 73 made a missed approach off RW12 with a 50kt tailwind at 1000' but a stiff seabreeze on the ground.
Wx today is blowing 35kts in 4000m viz. Argument enough you'd think to keep twr in place...

[Roger Standby]

Would hate to be separating YCBG circuit traffic with RPT stuff from where I am sitting.

Scurvy, must be frustrating for the ex radar tower guys to sit watching the tsad with heaps of room between a/c and not able to do anything but, at least on a good day, you guys still have the MarkI eyeball sep standard.

[Dick N. Cider]

Tassie Multilat - 18 groundstations which will provide significant enhancements to the Launceston "temporary" radar. The data will be fed into TAAATS but it's my understanding that it won't be integrated into the TSAD displays in Launy and Hobart. Was going to be but that was based upon a business case for sales O/S. No-one wants it now. Distinct possibility that the Melbourne based sectors will be able to see into the circuit but the towers won't.

Even with the TSAD available at locations with good radar coverage the towers are not allowed to use it for separation. It's an "...aid to developing situational awareness". Cuts out a lot of requests for reports - you wait until the aircraft is where you need the report and then make a single request. If they get rid of the Launy radar then presumably they'll have to supplement the towers. Even if all that comes off they still can't use it for surveillance services until the tower dudes have had some pseudo-radar approach training. I wouldn't be holding my breath.

"Identification terminated - contact tower..."

[Chief galah]

Essendon's TSAD is an approved radar.

[Dick N. Cider]

Chief Galah,

I apologise. Indeed it is. The others aren't and directly from the project manager I've been told that it's unlikely that they will be. There is a problem with data transfer delays at other than YMEN that render them invalid for separation services. I take a contrary view that they are still useable for limited services such as establishing outside latsep points and opposite direction passing. The error would always be on the safe side. This is being investigated.

[Scurvy.D.Dog]

.. my personal thoughts … and nothing else!!
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If the Primary in Sydney ‘craps out’, the techs should be on that site in LT pronto to commence dismantling for transport to SY!. …. Why? Because apparently there is not another TAR spare in the country ….the risk (in anyone’s language) is far greater at a location like SY …not to mention the fact that procedural controllers in LT do not come to a grinding halt if the big green eye falls over or is liberated by truck!!! ……so in the absence of ‘any other’ option … what would you do??
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… I am not aware of when the first of the new ‘heads’ will be delivered or if it will be the new transportable .. or if it would be available soon enough to be deployed immediately in SY … I am sure the seniors with all the info are on the case!
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.. the argument over whether Primary is required or desired in a regional D zone (pick any one you like) … is for a collective expert process to determine!
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…. In practical application, having that Primary coverage is ‘valuable’ to the D tower/approach controllers monitoring for rogue returns (on a workload permitting basis) in the lower levels of the terminal area where the risk (even whilst reasonably remote IMHO) of an un-notified, non-transponder equipped VCA aircraft is obviously most likely to occur!
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… I guess like all airspace ‘proposed’ changes it should be tested by wide peer review and against the ALARP principles. :ok:
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Hypothetically, the risk may be quantified as ‘acceptable’ (at certain traffic levels) to not warrant Primary … not sure what that threshold is or should be?! … and I am not sure how you obtain real VCA data when Prim has not been a feature at regional centres! ….. tis interesting to see how many general broadcasts result in CTR/A close proximity “Prim” targets magically turning away or calling up for a clearance .. thank goodness for VHF radio .. cheap and effective!
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… all that said, if you assumed for argument that secondary (dependant) surveillance is the minimum required standard in a given zone, there is another option that would mitigate (to some extent) against inadvertent primary only VCA’s … that is to subsidise the fitment of Mode C transponders in all aircraft capable of powering them and mandate it in ‘CTA/R’ classes (i.e MSSR and MLAT airspaces)! …… seems to me that you can power a mode C in anything (Gliders and the Sporties) that is likely to wander into a zone and big enough to create a threat … they are cheap enough nowadays to make subsidy money against safety benefit … money well spent!
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… the other side of that subsidy support is acceptance of mandating ‘auto on’ powered by air switch or squat switches to avoid inadvertent ‘off’
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… do these measures sufficiently mitigate against ‘Primary’ targeting ability?? No…. but they go bloody close .. balanced against cost benefit … it might fly in regional areas!! ….and save a heap! :)
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Re: remote services
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.. there is not doubt that some types of services can be provided remotely where surveillance exists! .. what services they are and how you make them work effectively??? … that’s the multi-million dollar question!!
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.. Christ .. where do ya start?? …. Lets do D Tower V’s C Centre to surface (it makes me giggle) :p
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… to do a remote service you might look at the following:-
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… A surface picture ….. you need to install a PSMR as the RPT’s disappear on the squat switches and the others are conditioned to turning them off manually automatically vacating the runway … yet providing PSMR to a regional tower is …apparently ….. pie in the sky?? .. hmmm ….
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… Oh … I know ….. Let’s pipe lots of camera’s back to lots of screens around an approach controller in the Centre …. That will be as effective …..they are really going to have good visual depth perception and the full picture of any manner of things going on around the airport …much much better and more reliable that eyes in the tower ……Aww sure ….. runway incursions is apparently not the only thing worth ‘filming’ though!. :E
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… then the pearler … no more ATS ‘tower provided visual separation’ … and … oh dear … Centre only have the anemometer and (maybe) surface display (hope that don’t fail cause you cannot just glance out the glass at a wind sock or taxiing aircraft) .. what cant they see that a tower controller can?? :ugh:
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…. Not to worry, Centre would have the auto METAR (… wish I had a dollar for every time that very clever device accurately described the weather immediately above the ground station yet the majority of the circling area was base 2,500ft AGL) and perhaps AWIS … beauty that’s heaps better and less prone to serious error than eyes in the tower … eww .. that will make approach selection fun .. imagine some of the ATIS’s :rolleyes:
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… hands up how many RPT pilots would opt for the ILS if there was any doubt about cloud base???? …. Crikey, that’s a lot of liquid gold (fuel) burnt unnecessarily …. .:hmm:
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… then the poor sods waiting to ‘go’ will just love the IMC runway roulette .. trying to decide if there is enough room to line up and go in front of one on approach in cloud?? …what would the Centre approach controller use to assess departure and arrival separation in IMC and VMC??? ….. could make for an interesting and very exciting formation takeoff/missed approachs into cloud … yih ha … thank goodness for TCAS … oops … not everyone has that?! :ooh:
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… then the grand daddy of them all ….. If tower controllers are not permitted to provide a radar service … how is it OK for a radar approach controller in the Centre permitted to look at all of the aerodrome data/equipment that might detract from looking at the radar and PSMR??? :=
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Besides, even if the cost of tower building were really factored into the equation with delay cost …. the cost benefit maths is difficult for this ol’ melon to comprehend!
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What are the comparative staffing requirements??
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.. If radar approach was deemed necessary at location X …. would Centre provided TMA be better than having the radar approach position in the tower?? Imagine what a ‘Screeny’ could do looking at the screen with the addition of windows as well ….. and lo and behold sitting right next to the ADC …… how much coordination (not just point to point) goes on between tower and remote TCU’s ……. Which is more streamlined?? …. and efficient??
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Infrastructure costs??
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I’m not even going there for fear of not being able to hold civilised keyboard decorum :mad:
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… there are other issues too lengthy to mention here ….. you’d all glaze over (more than you already are by now) and smash your melons into the keyboard!!
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… righto …so, rather than me waffle on as usual … how bout ya’ll think of:-
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- The sorts of things that can be piped via SAT/NET to the Centres?
- What are the contingencies if some or all of that information gets trashed??
- What will be the risks and delays of not having onsite eyes and equipment??
- What will be the comparative traffic movement capabilities??
- Is the usual and expected traffic quantity and type compatible with the class of airspace and service??
- How does IFER and AEP management compare?
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What is more likely in the end??
- Enroute controllers being trained and rated to do a function that is already being done by the tower???
- Tower/approach controllers rated to use radar to augment what they already do bloody efficiently?
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… I’m sure it will take years to decide! :uhoh:
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I have not heard that the towers will be denied access to MLAT data. I have in fact heard the opposite!
…. Besides, what sorta goose would be daft enough to remove an existing tool from tower/approach controllers?? .. now that would be an HazID process I would love to watch!! :}
…. Even the CEO said it would assist controllers with greater coverage!! .. I am sure he would not fib about that!! :oh:
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.. TSAD is a first step, it certainly ain’t the last!
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Re: the data latency issue ….. well if we cannot provide redundant paths to tower’s yet we can to enroute (who at the moment are not doing the approach terminal area stuff where it is as important if not more) …. Well I'll leave others to justify that decision!!! :hmm:
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…. That’s some of the CTR/A stuff … the OCTA/CTAF stuff is the interesting bit IMHO!
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I mentioned once before in this place some of the airspace utilisation possibilities … not gunna’ bore you again with that (here is the link for those interested)
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Airspace Architecture and associated - an alternative view
http://www.pprune.org/forums/showthread.php?t=229828
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… now **** off and let me watch the second half of the footy! :8 …. oohroo!

[jumpuFOKKERjump]

...18 groundstations which will provide significant enhancements to the Launceston "temporary" radar. Erm, I understand there will be 8 groundstations, an aircraft has to be within range of 3 to provide a return. The three have to be close together for ground monitoring, far apart for enroot. Once commisioned I don't think they'll need the present radar, and it may go before then anyhow.

Didn't mean to pick on your service Scurvy. I only wrote it like that coz the minister had just announced a new interest in NAS (it has taken him til now to read all the posts???). As your ceiling has been lowered to A085 by that silly process with no benefit anticipated or revealed it is likely it will continue to drop with the same result.

[peuce]

… then the poor sods waiting to ‘go’ will just love the IMC runway roulette .. trying to decide if there is enough room to line up and go in front of one on approach in cloud?? …what would the Centre approach controller use to assess departure and arrival separation in IMC and VMC??? ….. could make for an interesting and very exciting formation takeoff/missed approachs into cloud … yih ha … thank goodness for TCAS … oops … not everyone has that?! :ooh: !
I don't have an opinion either way yet, but some questions that your post raises for me ... what happens now when there's one inbound on the ILS in cloud and one wants to depart?

… how bout ya’ll think of:-
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- The sorts of things that can be piped via SAT/NET to the Centres?
- What are the contingencies if some or all of that information gets trashed??
- What will be the risks and delays of not having onsite eyes and equipment??
- What will be the comparative traffic movement capabilities??
- Is the usual and expected traffic quantity and type compatible with the class of airspace and service??
- How does IFER and AEP management compare?

Sounds very familiar ... closing on-site Flight Service Units (Broken Hill, Dubbo etc) and remoting them back to the Centres ... despite all the shortcomings you mentioned above, it went ahead ... If and when they seriously start talking about this stuff, you better have a good "money" argument on hand .. that's what talks these days!

P.S. The Broncos won!

[Scurvy.D.Dog]

… fair questions
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juFj Erm, I understand there will be 8 groundstations, an aircraft has to be within range of 3 to provide a return. The three have to be close together for ground monitoring, far apart for enroot. … I have heard 18 (around the state) .. just yesterday from the guy who will over see installation!! Once commisioned I don't think they'll need the present radar, and it may go before then anyhow. … you may well be right … but the reason would have to be VERY compelling as explained above …. You know the company charter …. Never unreasonably reduce safety levels etc etc!! :ok:
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peuce... what happens now when there's one inbound on the ILS in cloud and one wants to depart? …. Depends on cloud base, types and visibility. In short:-
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- If an Aircraft on a straight in precision approach can be established outside 5nm from the ‘threshold’ (in our case 6DME) by the time the departure is airborne, and consideration of missed approach is made i.e. if the arrival is a jet and the departure is a C404 then a greater margin is required, as well as options assessment i.e. once visual, would/could the jet fly a visual circuit pior to landing or is an IMC missed approach procedure required??
- If an aircraft is on a DME arrival, again cloud base and other factors such as possible missed approach are all considered in the mix.
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there are other considerations, those are just some of them!
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Sounds very familiar ... closing on-site Flight Service Units (Broken Hill, Dubbo etc) and remoting them back to the Centres ... despite all the shortcomings you mentioned above, it went ahead ... … true .. although ‘separation’ services are way different to ‘traffic services’ … interesting isn’t it that a return of ‘F’ is being seriously looked at!!!If and when they seriously start talking about this stuff, you better have a good "money" argument on hand .. that's what talks these days! … indeed! .... as should you guys 'the customers', cause it won't be my hip pocket that pays for the possible delays .... less for more ... sound familiar :( P.S. The Broncos won! .. who cares … I was referring to real footy :E …. The red and white ….. Go you good things …! :}

[Chapi]

:ok:

Guess it is official then! This will mean a radar-like service down to ground level at Launceston & Hobart with only mode C transponders in the aircraft!


Wide area multilateration went live today in Melbourne Centre.

Surveillance to the ground at Hobart plus ADSB coverage 250Nm around Tassie.

So when's the radar being relocated?

[Jabawocky]

Bugger!

I wont be able to sneak into Launie with a surprise attack on Scurvy D Dog then :}

[Capn Bloggs]

So when's the radar being relocated?
On the 1st of April...to Karratha! :}

PS. No dogs allowed! :}:}

[fanning]

Just following up from the above comment RE this not being displayed in the TSAD.

Heard on the airwaves this morning, Hobart Tower talking to some VFR planes, that they could seem them on their "new system", so presumably the feed IS going into HB and LT TSAD's :confused:

[Jabawocky]

Sounds good...... but I want the ILS, even if its 8/8ths and VMC :}

In fact if it is, I reckon the Dog might get some Retard Time! :ok: Last time I flew with him the bastard was disgustingly good! :suspect:

[Dick Smith]

"When commissiond in early 2008"

So what's happened? Surely not another Super Seasprite disaster?

[le Pingouin]

What's happened? It's commissioned is what. Maybe you need to check out the vision correction thread :}

As Chapi mentioned on the 12th: Wide area multilateration went live today in Melbourne Centre

[Dick Smith]

Does that mean it is actually commissioned and certified to separate aircraft?

What's the separation standard approved?

[Freedom7]

It is certified for separation utilising both WAMLat triangulation and ADS-B. 5nm

Ask CASA why it took longer than anticipated to commission

[Dick Smith]

CASA, why did it take so long to commission?

[CrazyMTOWDog]

The Muppet thread is not here.

[le Pingouin]

Why so long? It's new technology so needs all manner of approvals, supporting evidence to prove it's up to the task & can be integrated into the current system? Just little things like that.

The accuracy is apparently considerably better than SSR radar.

[PLTOFF4LIFE]

an aircraft has to be within range of 3 to provide a return.

Actually you need at least 4, sorry to be a nerd

[LeadSled]

PLTOFF4LIFE (http://www.pprune.org/members/189009-pltoff4life)
How did you work that one out --- theoretically at least, all you need is two to fix a position. However , I do accept that the more the merrier, or more particularly, the more you have, the smaller the CEP.
Tootle pip!!

[ARFOR]

3 needed for minimum 'accurate' triangulation [azimuth accuracy] + plus one for single point failure redundancy.

Is my guess :E

[le Pingouin]

the smaller the CEP.
That is the point!

[MrApproach]

The separation standard in TAS is 5 nm and the MLAT also receives any ADS-B that might be around. It is used in ML for separation and displayed on TSAD, but TSAD is a situational awareness tool not a separation tool. Upgrades and ASA decision required to use for approach control. LT and HB radar towers, I don't think so!

SY is now being multilaterated to replace the PRM. Even more accurate multilat than Tassie. 3 nm separation in TMA and PRM separation on final approaches to 16/34 parallels. I'm told no procedure changes so you pilots will not notice the difference. PRM controllers however will, display will look more like Eurocat.

[Starts with P]

PRM controllers however will, display will look more like Eurocat.
Does that mean we get an upgraded sim as well? Maybe run it on a 386? :} :ok: