An ADS-B In Question

On Tuesday, February 9, 2016 at 7:50:02 PM UTC-8, Mike Schumann wrote:

Hey Mike - if I'm misinterpreting it then so is AOPA (not that it's impossible). Take a look here, starting at 4:55.

http://www.aopa.org/AOPA-Live?watch=...88197D11A94%7D

9B



I believe that you are totally misinterpreting the information in the AOPA link you provided. While AOPA has been lobbying for years for the FAA to transmit all TIS-B data so that aircraft without ADS-B OUT will have access to this data, this is NOT what the FAA is doing. Instead, the FAA is actually clamping down and will no longer transmit TIS-B data to aircraft that are equipped with ADS-B OUT equipment that use GPS position sources that do not meet minimal performance standards.

If you want to reliably receive TIS-B data from an ADS-B ground station, your aircraft MUST be ADS-B OUT equipped.

Note: PowerFLARM does not support TIS-B and there has been no information provided by anyone that they are even thinking about adding this functionality to their product. That's a huge shortcoming in the product that is certainly not helping their sales efforts.

On Wednesday, February 10, 2016 at 12:06:59 AM UTC-5, Andy Blackburn wrote:

Hey Mike - if I'm misinterpreting it then so is AOPA (not that it's impossible). Take a look here, starting at 4:55.

http://www.aopa.org/AOPA-Live?watch=...88197D11A94%7D


But there is no approved implementation plan for doing what AOPA wants. Whether it is technically feasible within the hard constraints remains to be proven.

What I heard was that the FAA has agreed to /_work with_/ AOPA towards
implementing a solution, not that they've agreed to do anything. Still,
there's hope...

On 2/10/2016 7:03 AM, son_of_flubber wrote:
On Wednesday, February 10, 2016 at 12:06:59 AM UTC-5, Andy Blackburn wrote:

Hey Mike - if I'm misinterpreting it then so is AOPA (not that it's impossible). Take a look here, starting at 4:55.

http://www.aopa.org/AOPA-Live?watch=...88197D11A94%7D

But there is no approved implementation plan for doing what AOPA wants. Whether it is technically feasible within the hard constraints remains to be proven.

--
Dan, 5J

On Tuesday, February 9, 2016 at 9:50:02 PM UTC-6, Mike Schumann wrote:

I believe that you are totally misinterpreting the information in the AOPA link you provided. While AOPA has been lobbying for years for the FAA to transmit all TIS-B data so that aircraft without ADS-B OUT will have access to this data, this is NOT what the FAA is doing. Instead, the FAA is actually clamping down and will no longer transmit TIS-B data to aircraft that are equipped with ADS-B OUT equipment that use GPS position sources that do not meet minimal performance standards.

If you want to reliably receive TIS-B data from an ADS-B ground station, your aircraft MUST be ADS-B OUT equipped.

Mike, please go back and carefully re-read the AOPA article. While poorly written, it specifically states that the FAA is implementing 2 changes: First, it will allow aircraft with non-conforming ADS-B out to be seen by certified ADS-B in (which covers people with experimental setups - perhaps even a Powerflarm GPS hooked up to a Trig TT21? Darryl, comment?) and second, it gets rid of the "hockey puck" limitation on TIS-B traffic transmission, so now anyone with an ADS-B IN receiver will see all the TIS-B traffic around them, not just traffic sent to a nearby certified ADS-B out-equipped aircraft.

It does talk about "certified ADS-B receivers". Does that include the inexpensive ones used with a tablet or smartphone? I may need to look into that myself.

Note: PowerFLARM does not support TIS-B and there has been no information provided by anyone that they are even thinking about adding this functionality to their product. That's a huge shortcoming in the product that is certainly not helping their sales efforts.

Again, PowerFLARM does EXACTLY what it was designed for - provide glider-to-glider (with some additions, like british military aircraft) COLLISION AVOIDANCE information, with the added benefit of seeing all mode S ADS-B and Mode C transponder aircraft nearby. It is optimized for the European environment (no idiotic UAT) but works pretty damn well here in the US. Now, it looks like adding an inexpensive ADS-B in receiver will get TIS-B into your glider cockpit even if you don't have an ADS-B out setup.

It'll be interesting to see what glider nav setup first incorporates the ability to display TIS-B traffic - I'm hoping SYM on my Oudie will!

Kirk
66

On Wednesday, February 10, 2016 at 10:29:20 AM UTC-5, Dan Marotta wrote:
What I heard was that the FAA has agreed to work with
AOPA towards implementing a solution, not that they've agreed to do
anything.* Still, there's hope...




On 2/10/2016 7:03 AM, son_of_flubber
wrote:



On Wednesday, February 10, 2016 at 12:06:59 AM UTC-5, Andy Blackburn wrote:



Hey Mike - if I'm misinterpreting it then so is AOPA (not that it's impossible). Take a look here, starting at 4:55.

http://www.aopa.org/AOPA-Live?watch=...88197D11A94%7D



But there is no approved implementation plan for doing what AOPA wants. Whether it is technically feasible within the hard constraints remains to be proven.





--

Dan, 5J

The video is the 1st information that I have seen that indicates that the FAA is looking into opening up the TIS-B system to ADS-B IN only users. That's great news. Realistically though, it's going to be a year or two before this actually is implemented.

Now if the PowerFlarm guys would get their act together and support TIS-B......

On Tuesday, February 9, 2016 at 11:30:04 AM UTC-8, Andy Blackburn wrote:
Some news on TIS-B services.

It appears that the FAA will be modifying TIS-B to make it available to anyone with an ADS-B receiver, regardless of ADS-B Out carriage. This means that you should be able to see rebroadcast of all transponder-equipped (as well as "opposite-band" ADS-B Out) aircraft within range of SSR with resolution as good as a few hundred feet simply by acquiring one of the relatively inexpensive ($100-150) ADS-B receivers. It may be available as early as this summer. It appears that this will enable a "God's eye view" of all transponder-equipped gliders (and other aircraft) in a broad flying area so long as there is SSR coverage. It remains to be confirmed whether or not PowerFLARM ADS-B In can decode TIS-B traffic. My understanding is that nothing special was included in the PowerFLARM design to accommodate TIS-B, but I am unsure whether TIS-B traffic resembles ADS-B direct transmissions closely enough to be decoded by PowerFLARM anyway. Either way there ought to be a glider-relevant solution available this year.

http://www.aopa.org/News-and-Video/A...anges-to-TIS-B

Additionally, it seems that the FAA will now rebroadcast ALL traffic regardless of ADS-B Out performance and configuration. Previously, some aircraft would not be rebroadcast if their ADS-B Out did not meet certain performance criteria and, as a result, would effectively be invisible so far as TIS-B services were concerned.

Things are moving pretty quickly. Surprising.

9B

Ah Nope you are reading this largely backwards... and you know what... this has been gone over on r.a.s recently in detail....

On Tuesday, February 9, 2016 at 8:12:41 PM UTC-8, JS wrote:
I read the AOPA article the same way Andy does.
The ghosting thing is a problem, alarms that "you're near yourself" are useless.
But that's always been a problem with non-FLARM proximity warnings, the algorithms are not set for simple things like sharing a thermal.
Jim

Jim, you and Andy are reading it wrong, but it seems many other are as well.. The writing/"reporting" in the AOPA article is just embarrassingly bad. AOPA should be helping educate their members and instead they write this confusing crap. They should be making sure to explain what the FAA is doing is more opposite to what they have been wanting. I'm not picking sides here on the technical argument for or not for "open TIS-B", I am picking on AOPA for just awful reporting/clarity/education of their membership. Maybe they are too embarrassed to state clearly the FAA is **NOT** doing what they want them to do.

And like many things ADS-B related I've tried to clarify this particulat mess before, e.g. see the bottom part of this thread https://groups.google.com/forum/#!to...ng/F-hMpqQ_VBU

Crap! Sorry all.

On Wednesday, February 10, 2016 at 7:47:03 AM UTC-8, kirk.stant wrote:
On Tuesday, February 9, 2016 at 9:50:02 PM UTC-6, Mike Schumann wrote:

I believe that you are totally misinterpreting the information in the AOPA link you provided. While AOPA has been lobbying for years for the FAA to transmit all TIS-B data so that aircraft without ADS-B OUT will have access to this data, this is NOT what the FAA is doing. Instead, the FAA is actually clamping down and will no longer transmit TIS-B data to aircraft that are equipped with ADS-B OUT equipment that use GPS position sources that do not meet minimal performance standards.

If you want to reliably receive TIS-B data from an ADS-B ground station, your aircraft MUST be ADS-B OUT equipped.

Mike, please go back and carefully re-read the AOPA article. While poorly written, it specifically states that the FAA is implementing 2 changes: First, it will allow aircraft with non-conforming ADS-B out to be seen by certified ADS-B in (which covers people with experimental setups - perhaps even a Powerflarm GPS hooked up to a Trig TT21? Darryl, comment?)

Well yes and no. See below for more. The only change actually happening now will make the glider in your scenario visible to aircraft with certified ADS-B In receivers but it does so only by creating a TIS-B target for your glider, relying on SSR/Transponder positioning and broadcasting that to the client aircraft. So obviously that only works within SSR coverage, and still only broadcasts TIS-B data about that glider if it is within the "hockey puck" of an aircraft with a complaint ADS-B Out system.

and second, it gets rid of the "hockey puck" limitation on TIS-B traffic transmission, so now anyone with an ADS-B IN receiver will see all the TIS-B traffic around them, not just traffic sent to a nearby certified ADS-B out-equipped aircraft.

No. To be clear what you are talking about is futureware/hopeware and nothing to do with what is actually happening now. See below.


It does talk about "certified ADS-B receivers". Does that include the inexpensive ones used with a tablet or smartphone? I may need to look into that myself.

A certified ADS-B receiver (and display) being talked about by the FAA here is something like say in the low/mid-range GA market is say a new Garmin GTX 345 connected to a GTN650 display. If an avionics shop is installing it in a certified aircraft in your panel then it's one of those. Portable ADS-B receivers connected to iPads, tablets, etc. are *not* one of those.


Note: PowerFLARM does not support TIS-B and there has been no information provided by anyone that they are even thinking about adding this functionality to their product. That's a huge shortcoming in the product that is certainly not helping their sales efforts.

Again, PowerFLARM does EXACTLY what it was designed for - provide glider-to-glider (with some additions, like british military aircraft) COLLISION AVOIDANCE information, with the added benefit of seeing all mode S ADS-B and Mode C transponder aircraft nearby. It is optimized for the European environment (no idiotic UAT) but works pretty damn well here in the US.

No argument there.

Now, it looks like adding an inexpensive ADS-B in receiver will get TIS-B into your glider cockpit even if you don't have an ADS-B out setup.

No it won't. Not today. And even if it does in future how you can or cannot connect any of this stuff is a significant issue.

It'll be interesting to see what glider nav setup first incorporates the ability to display TIS-B traffic - I'm hoping SYM on my Oudie will!

Kirk
66

OK more details...

The AOPA article is describing two things. I'll explain it more clearly since I see it is still causing confusion. Those two things a

1. What the FAA is doing now (TIS-B target broadcasts of non-complaint ADS-B out as is documented by the FAA here https://www.faa.gov/nextgen/programs...-15-webV2.pdf). And again, this #1 thing currently happening has nothing to do with getting rid of the need to have complaint ADS-B Out to receive ground based services like TIS-B, it just makes TIS-B traffic data for aircraft with complaint ADS-B Out available to those client aircraft that are ADS-B Our and ADS-B In equipped. previously ADS-B In Certified/IFR class systems would not display those ADS-B targets (yes you cannot make this stuff up). And what is being done here is. The other part of what is being done here is actually to stop broadcasting TIS-B and ADS-R for non-complaint ADS-B Out client aircraft.... so actually that is kind of opposite of that the FAA wants... (in #2 below).

and

2. talking about what AOP wants the FAA to do in future, which is open TIS-B broadcast or something similar. In principle that might mean no client aircraft/hockey puck needed. In practice what it exactly means is... well... wait and see exactly. The video referred to above is only refers to this second thing AOPA wants the FAA to do.

The FAA is right now rolling out # 1. they are investigating # 2. Actually "working on a plan". So again lets see where that leads and see exactly what they are talking about before worrying too much about the details. It may or may not be technically possible to do exactly what people want with this everywhere.

I suspect neither #1 or #2 FAA action will have little if any affect on USA glider pilots as PowerFLARM does not receive TIS-B. And few gliders have ADS-B Out anything, wether compliant of not, so not much practical increase in observability of those gliders, still maybe useful to know for folks in some areas...

And for the Airliners and fast jets, they get to rely on TCAS so that works regardless of what ADS-B anything the glider has, just as long as it has a transponder. Oh and don't rush to add UAT-Out thinking change #1 mean anybody else will see you, the FAA us just using TIS-B here, the FAA ground infrastructure needs the SSR/transponder location to generate that data. Fly around with UAT Out and no transponder, or outside SSR and ADS-B base station coverage and those certified ADS-B In systems still won't see your glider with an approved ADS-B Out. That well equipped Kind Air or PC-12 who's pilot thinks his certified ADS-B In system can see everything? Bzzzzzt wrong! Down low out in the traffic pattern of a remote airport they'll just run right over the top of a glider with a non-complaint ADS-B Out install without even a beep. (so ideally do a complaint install if you want ADS-B out now, or wait for TABS... *if* TABS regulations happen then that should provide lower cost ways of providing complaint ADS-B Out which will be seen by all 1090ES In equipped aircraft in all situations).

Even if somebody makes a separate ADS-B UAT receiver or box able to merge FLARM and UAT data together it might not deliver a very usable product/significant enhancement over current PowerFLARM systems for most glider pilots. And folks need to be very careful talking about all this home grown/crowd-funded toys maybe eventually doing anything like this. Its one thing to play with stuff, or hope to just display traffic, but it's a very different thing to generate a FLARM like traffic warning. So hands up who would want a box that can display ADS-B traffic on your current soaring flight computer but will/can not issue any warning at all as you collide with a threat? ... and to be clear to everybody that is exactly what Andy is proposing that crowd funded project actually do. So lets separate our interesting to play with toy ideas from an actually usable collision awareness system like FLARM (or even a modern ADS-B In receiver which does its own style crude and less useful for gliding audible traffic warnings). For the later this seems to me like stuff that I'd want only FLARM doing.

TIS-B location data is derived from SSR/transponder data and so i much less precise than GPS derived FLARM or standard ADS-B. And where that data is generated from a Mode C (vs. Mode S) transponder it is much harder to deduplicate (part of the reason that there will be increased ghosting caused by the FAA change #1 on uncertified (e.g. portable) ADS-B in systems). How a FLARM like system would handle that is a research project that likely really needs FLARM R&D like skills, but I doubt it is worth FLARM investing in this for marginal benefit for the small US glider market (doing basic integration with outboard UAT In receivers to enable dual-link receive or adding ADS-R support on the other hand I could see being more useful).

Dang, stupid ADS-B crap. I knew I would screw this up (one beer, now on my second). I left the NON- off NON-complaint in a critical sentence and left off CERTIFIED in another part of the sentence.. so I'll try again...

" it just makes TIS-B traffic data for aircraft with NON-complaint ADS-B Out available to those client aircraft that are equipped with CERTIFIED ADS-B Out and ADS-B In."

I am sure there are other typos but I'm about to run out of beer.