New contract for Tasmania

[flywatcher]

What is multilateration. Is this a new name for ADS-B? What is going on now?



Media Releases

Improved 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.

For further information contact
Airservices Australia Media
Ph: +61 2 6257 2828
Mb:

[Capt Claret]

New contract for Tasmania

Sheesh. At last. Some one's gonna buy the place! :p :8

[PLovett]

Now now clarrie.................just because land prices are cheaper there it doesn't mean the inhabitants are. :E

[SM4 Pirate]

From what I know, which isn't much...

WAM, simply triangulates the mode C pulse; you have to be in range of at least three sites to get a very accurate 'position'; without the expense of radar equipment. The WAM receivers are about $200K a piece and similar to an ADS-B box in size, ie about the same size as your average bar fridge. So they can be located just about anywhere there is power and a phone line, virtually maintenance free as there are no moving parts. I believe there is still some sort of display if not in range of three boxes, but it's less accurate.

Biggest difference you'll notice is the interrogation light flashing constantly (scans once a second I think, which could be a constant flash on occassions as the pulse from each box reaches you at a different moment in time)... These could be the way to go, in lieu of low-level ADS-B; as there is no chance of "interference", but most importantly there is almost no cost to industry as nothing new required airborne (assuming most kit has a mode C transponder).

Main difference between ADS-B and WAM is you must be in range of at least 3 boxes for it to work "accurately". ADS-B needs only one in range to get the information out of your squitter, which is GPS info.

WAM are used for SMC displays and precision approach monitoring overseas.

I guess they are a bit of an experiment in terms of enroute use, but many Tassie peaks gives a great opportunity to test this stuff; it won't be used until it's been proven against the current radar coverage; of course just like MSSR it relies on the aircraft playing the right games when using transponders, i.e. turn them on and if ALT (mode C) equipped select it.

Just waiting for the his royal highness to say this is a bad thing… :E

[Roger Standby]

Say goodbye to the Radar at YMLT. Rumour has it thay need it in Sydney. Let's see if they can get this new system up and running before they rip the old one out.