WAM now called "NexGen" too...

[denverpilot]

... now with more Marketing BS and spin!

From AvWeb: http://www.avweb.com/eletter/archives/bizav/2388-full.html#207793

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FAA NextGen Technology Expands In Colorado


New technology now available will help pilots better cope with bad weather in the mountains near Montrose, in the western part of Colorado, the FAA said this week. The Wide Area Multilateration (WAM) system makes it possible for air traffic controllers to track aircraft in mountainous areas that lack radar coverage, the FAA said. "This system will allow pilots to fly search and rescue missions in weather conditions that would have previously kept them grounded," said Michael Huerta, acting FAA administrator. The system also will enable pilots to land in conditions that previously caused diversions or flight delays, Huerta said.

WAM is a NextGen technology that tracks aircraft using a network of small sensors deployed in remote areas, the FAA said. Aircraft transponders receive and send back signals to these sensors. System computers immediately analyze those signals and determine the aircraft's precise location. The system has also been deployed in Alaska and in Canada. WAM is being used in the near-term until ADS-B is fully deployed, according to the FAA. WAM will then serve as a backup to ADS-B in case of a GPS outage, and also will provide an additional surveillance source for ADS-B traffic broadcasts.

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My favorite BS in this one...

"will help pilots better cope with bad weather in the mountains near Montrose"... Really? Wow... how will the controller knowing where I am help me cope with weather?

"This system will allow pilots to fly search and rescue missions in weather conditions that would have previously kept them grounded"... BWAHAHAHAHAHAHAHAAHAHAH! Oh wait, let me catch my breath... BWAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAH!

(Suppose the idiot meant RESCUE CALLSIGN missions, as in... MEDEVAC FLIGHTS?!?! What the hell are you going to use to SEARCH for people with in bad weather? LIDAR? Christ... government idiots...)

"The system also will enable pilots to land in conditions that previously caused diversions or flight delays, Huerta said." -- Really? Did the approaches change down there to say "WAM REQUIRED"? ROFL!

Ahhh... so after ALL the BS... the REAL reason comes...

"WAM will then serve as a backup to ADS-B in case of a GPS outage, and also will provide an additional surveillance source for ADS-B traffic broadcasts."

Duh.

I truly f-ing hate the PR spin put on NexGen by FAA. I really really do.

 

[Clark1961]

Nate - Have you considered de-caf as a viable alternative?

 

[wabower]

It appears that the 36's may be a bit tight. A pair of 38's might be more comfy, less binding.

Nate - Have you considered de-caf as a viable alternative?

 

[Piloto]

Multilateration has been in use for over ten years in different part of the world. The only limitations is that the airplane need to be in view of two ground stations to get a position fix. The other is that you need a long base line between stations to locate traffic at long distances. A multilateration system would not work for Bermuda or a ship due to the short distances for multiple stations. On the other hand there is no special equipment required for the aircraft like ADS-B. And unlike ADS-B, multilateration systems are spoof resistant but not jam proof like conventional radar. As far as cost it is all relative. A conventional single point radar requires less real state than multilateration systems and the logistics of providing maintenance, power, security and data links are less complicated for a single point radar.

José

 

[murphey]

Multilateration has been in use for over ten years in different part of the world. The only limitations is that the airplane need to be in view of two ground stations to get a position fix. The other is that you need a long base line between stations to locate traffic at long distances. A multilateration system would not work for Bermuda or a ship due to the short distances for multiple stations. On the other hand there is no special equipment required for the aircraft like ADS-B. And unlike ADS-B, multilateration systems are spoof resistant but not jam proof like conventional radar. As far as cost it is all relative. A conventional single point radar requires less real state than multilateration systems and the logistics of providing maintenance, power, security and data links are less complicated for a single point radar.

José

Jose'

Excellent summary of WAM for those not familiar. For those of us in Colorado, it's been up and running in the Steamboat area for quite a while. In fact there are people on this list that spent hours doing holds in that area so the FAA could test/whatever the system. The Montrose/Durango system is the new one.

Isn't is fascinating the systems are going in at the high-end ski areas?

 

[Jim_R]

My favorite BS in this one...

"will help pilots better cope with bad weather in the mountains near Montrose"... Really? Wow... how will the controller knowing where I am help me cope with weather?

I routinely hear ATC provide advisories to pilots about weather they're approaching, and if the pilot's on an IFR plan, either soliciting intentions or proactively providing authorization to deviate from assigned course in some direction. I would think this service would be more difficult to provide if ATC couldn't clearly see where the plane and the weather were projected to be in the future.

 

[Jim_R]

Multilateration has been in use for over ten years in different part of the world. The only limitations is that the airplane need to be in view of two ground stations to get a position fix.

Wouldn't you need three stations? (Imagine two pins in a bulletin board with a piece of string tied to each. Put the tips of the string together and pull taut, and you can swing that point through a 180deg arc of possible positions. Add a 3rd pin and string and you get only one solution.)

If you trust the altitude reported by the transponder, you could narrow down to two possible positions with two base stations. To get better than that, you'd still need a third base station, or else you'd need at least some limited directional sensing capability in the base stations.

As far as cost it is all relative. A conventional single point radar requires less real state than multilateration systems and the logistics of providing maintenance, power, security and data links are less complicated for a single point radar.

I would think that physical limitations of terrain are what drive you to multilateration, and that's where it becomes cost-effective. Multiple rigid antennas and radio shacks around the mountains and wilderness vs. multiple rotating radars to achieve the same coverage. Fundamentally, I'd expect a multilateration station to look a lot like a cell phone tower, and the cell companies have certainly figured out how to stick those things everywhere.

 

[Clark1961]

I routinely hear ATC provide advisories to pilots about weather they're approaching, and if the pilot's on an IFR plan, either soliciting intentions or proactively providing authorization to deviate from assigned course in some direction. I would think this service would be more difficult to provide if ATC couldn't clearly see where you were and where the plane and the weather were projected to be in the future.

I think we're dealing with at least a couple perspectives here. For us "little airplane" drivers, if we're over the mountains then we're mostly VFR and can see the weather. The FAA is catering to the bizjets & airliners (and the occasional twin driver like Doc C. who knows what he is doing) who will poke their heads in the clouds over the mountains. From the FAA's perspective they are helping the pilots.

Of course Nate is correct about little or no help for SAR. Hopefully the bobblehead meant medivac and just mis-spoke. It happens.

With all this said, ATC has been very helpful when I've asked about weather while over the hills. Of course I've flown around Colorado enough that I usually know what I have to do to be seen on radar and make that happen before asking questions. WAM does help. ADS-B out would be much better.

 

[Everskyward]

The biggest "help" is for IFR pilots who previously had to hold until the preceding airplane was on the ground before starting the approach. In the same vein they would not be able to get an IFR release when taking off until the preceding airplane was in radar contact. This increases the capacity of the airport and cuts down on delays.

 

[Kevin H.]

"This system will allow pilots to fly search and rescue missions in weather conditions that would have previously kept them grounded."

He Bob, have you seen those missing hikers we're looking for? Nope, all I've seen for the past hour is this big overcast cover. Oh well, thank goodness we have "WAM." What the heck?

 

[NoHeat]

What signal from the aircraft is sensed by the ground-based sensors. Transponder?

 

[Clark1961]

What signal from the aircraft is sensed by the ground-based sensors. Transponder?

yup...supposedly the WAM in the southern portion of Colorado includes ADS-B but I didn't receive any data last time I was in the area.

 

[flyingron]

NEXGEN is rapidly becoming the same nonsense as 4G in Cellular.

 

[denverpilot]

What signal from the aircraft is sensed by the ground-based sensors. Transponder?

Yes. Ground stations at known fixed positions listen for the transponder after a central ground omnidirectional transmitter triggers it. (Normally the transponder is triggered by that bar antenna on top of the rotating primary RADAR antenna going round and round. It's angled slightly behind the main antenna by a small margin.

By calculating time round-trip, a WAM system can triangulate the aircraft location.

But it has zero to do with NexGen and can be deployed without a smidge of ADS-B installed anywhere.

 

[Henning]

Yes. Ground stations at known fixed positions listen for the transponder after a central ground omnidirectional transmitter triggers it. (Normally the transponder is triggered by that bar antenna on top of the rotating primary RADAR antenna going round and round. It's angled slightly behind the main antenna by a small margin.

By calculating time round-trip, a WAM system can triangulate the aircraft location.

But it has zero to do with NexGen and can be deployed without a smidge of ADS-B installed anywhere.

Budgetarily is it considered NexGen? Wouldn't it also be incorperated into that system?

 

[Clark1961]

Budgetarily is it considered NexGen? Wouldn't it also be incorperated into that system?

The budget issue was a separate one with the state of Colorado. Maybe the FAA wrote it in a Nexgen but they weren't the only ones involved. I believe the WAM initiative started in Colorado rather than some FAA vision.

 

[denverpilot]

The budget issue was a separate one with the state of Colorado. Maybe the FAA wrote it in a Nexgen but they weren't the only ones involved. I believe the WAM initiative started in Colorado rather than some FAA vision.

Correct. Colorado Division of Aeronautics split costs with FAA on all three WAM systems I believe. The first had a proof of concept portion to it since it had to feed aircraft location data into ZDV and be scrutinized heavily to make sure it was working right. Seems like they've got that part down pat now and can more easily add on more areas now.

CDOT/Aeronautics rarely gets any credit in the press for it outside of aviation circles, though. FAA has more people with time to talk to the press and call it all NexGen, falsely. CDOT/Aeronautics isn't quite as loud about their portions of things. They probably like it that way, but I for one am thankful we have a clueful Aeronautics branch in the State. So many States neglect it.

Most of the Mountain AWOS stations are Colorado-funded too. And located on State of Colorado radio sites, not FAA ones. And connectivity is Colorado-paid wireline or microwave.

Aeronautics had a big loss in the last couple of years when a very good person moved on to other things. I hope his successor is as good as he was. It's seeming so far like he's working out judging only by results. I'm not close to any of the players in that game.