focal_plane
Pre-takeoff checklist
Is anyone familiar with a solution? I've done some searching but haven't hit on the answer.
Portable ADS-B In w/ 496 Family Interface?
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kontiki
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Getting the data in is one thing, what your going to use it for is another.
At the airline level, using specialized surveillance processors (TCAS plus ADS-B in) I've seen demos or or heard about the following proposed applications:
Surface Area Movement Management
Merging and Spacing (UPS supposedly uses this)
In Trail Passing (Airbus inovation)
ADS-B Assisted Visual Separation
Closely Spaced Parrallel Approaches
Note that some of the applications require specialized display or control hardware to work. None of the airline gear I've seen even recognizes UAT ADS-B out.
When I've asked how surface area movement management would work when you can't recieve and data from GA aircraft on the field, the sales
people glaze over and keep repeating the last line of the PPT slide.
The FAAs dual ADS-B frequency use isn't too helpful on the ground because line of sight from a repeater isn't there and the latencies are probably too much for aircraft that close.
At the airline level, using specialized surveillance processors (TCAS plus ADS-B in) I've seen demos or or heard about the following proposed applications:
Surface Area Movement Management
Merging and Spacing (UPS supposedly uses this)
In Trail Passing (Airbus inovation)
ADS-B Assisted Visual Separation
Closely Spaced Parrallel Approaches
Note that some of the applications require specialized display or control hardware to work. None of the airline gear I've seen even recognizes UAT ADS-B out.
When I've asked how surface area movement management would work when you can't recieve and data from GA aircraft on the field, the sales
people glaze over and keep repeating the last line of the PPT slide.
The FAAs dual ADS-B frequency use isn't too helpful on the ground because line of sight from a repeater isn't there and the latencies are probably too much for aircraft that close.
focal_plane
Pre-takeoff checklist
What I was looking for was a similar capability of some of the "i" devices with ADS-B portable receivers (Stratus, Skyradar). I don't recall seeing one with an interface to the garmin portables. Seems like trafic info through the power/serial port and wx through the wx port might be possible, at least for the 496, I'm not familiar with the aera/696/796 architecture. Seems like a number of folks might use this option who are getting wx from Sirius. Might not be technically feasible though, just a question.
denverpilot
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Someone posted in another thread that Garmin is hinting that they'll do their own ADS-B In receiver. No hints on release date.
JGoodish
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I would think that a software update would be required to the 396/496 to accept the ADS-B format data rather than the expected XM. This would require new software development work on discontinued hardware, which I suspect that Garmin has no incentive to do.
The receivers for tablets use WiFi to communicate with the tablet, so there is no hardware interface issue. The software that displays the data is an app, which is typical subscription-based, ensuring continuous revenue for its development. Completely different model.
JKG
Piloto
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To keep sales going must likely it will be a new Garmin portable product with the UAT receiver built in, just like the GPS receiver. It will probably be around $1000 to compete with the current ADS-B+Ipad configurations
José
José
focal_plane
Pre-takeoff checklist
I agree, Garmin has very little incentive to support a SW/FW upgrade. If I were designing an interface, I'd format the ads wx data to look like the XM wx data looks so no Garmin change required. Same with the traffic display which companies like Zaon have done. The way I wrote that "make the ads wx data look like xm wx data" sounds trivial; I suspect it's not otherwise we would have seen it hit the market. With all of the X96 devices out there and most folks' desire to get off the XM grid, it seems like there would be a pretty good market for it. These folks claim to have an X96 interface for ADS WX and TIS-A:
http://www.navworx.com/experimental-aircraft.php
The block diagram only shows the RS-232 TIS interface plus it's not really a portable installation. Little pieces here and there but still searching for the right solution.
http://www.navworx.com/experimental-aircraft.php
The block diagram only shows the RS-232 TIS interface plus it's not really a portable installation. Little pieces here and there but still searching for the right solution.
focal_plane
Pre-takeoff checklist
I might go for that. A little less than 2 years of XM subscription plus traffic.
kontiki
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There are a couple of different things going on.
ADS-B Out -> your aircraft transmits GPS coordinates (and other data)
Above FL 240 Must be 1090 MHZ
Below FL240 can use UAT 978 MHZ.
FAA plans ground based repeater to allow one group to obtain data from other. That is ADS-R uplink repeater from ATC.
There are other ATC uplinks.
TIS= Surveilance Radar information uplink - in service now in active TCA
FIS - Flight Information Service, supposed to be free weather uplink from FAA
Generally, I don't think of the uplinks as ADS-B IN. Companies selling gear for the big iron are pitching recievers that recieve ADS-B OUT from other aircraft directly, no uplink.
If you just want to see whos around you (given some latency) on a VFR flight, it's not a big deal. I really like TIS when I'm up practicing manuvers.
Some of the applications I mentioned in an earlier post involve ATC turning over some measure of the responsibility that have for maintaining IFR separation, to cockpit of appropriately equipped ADS-B in aircraft.
ADS-B Out -> your aircraft transmits GPS coordinates (and other data)
Above FL 240 Must be 1090 MHZ
Below FL240 can use UAT 978 MHZ.
FAA plans ground based repeater to allow one group to obtain data from other. That is ADS-R uplink repeater from ATC.
There are other ATC uplinks.
TIS= Surveilance Radar information uplink - in service now in active TCA
FIS - Flight Information Service, supposed to be free weather uplink from FAA
Generally, I don't think of the uplinks as ADS-B IN. Companies selling gear for the big iron are pitching recievers that recieve ADS-B OUT from other aircraft directly, no uplink.
If you just want to see whos around you (given some latency) on a VFR flight, it's not a big deal. I really like TIS when I'm up practicing manuvers.
Some of the applications I mentioned in an earlier post involve ATC turning over some measure of the responsibility that have for maintaining IFR separation, to cockpit of appropriately equipped ADS-B in aircraft.
JGoodish
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The bigger question is, why would anyone want to support legacy systems when they have a huge emerging market? I suppose the data could be reformatted, but among other concerns, I would think that opens an unnecessary liability risk should there be a problem.
In addition, there is not a direct correlation between the suite of XM products and ADS-B products. The Garmin portables also don't support WiFi, which is the dominant method of connectivity for portable ADS-B receivers, so a serial connection would be required. And at the end of the day, what could be displayed without software changes on the Garmin would be, at best, incomplete.
JKG
focal_plane
Pre-takeoff checklist
All good points. And maybe there's just too much risk all the way around to bring something like this to market. I'm really not an "i" guy so I'll continue to look for an alternative. I have worked with tablets but I prefer the quasi pure aviation devices that I don't strap on my leg. If Garmin integrates an ADS-B receiver into a future release, that would certainly be a positive factor for buying.
Piloto
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Having all in one box plus the Garmin product reputation beats all the current ADS-B options.
José
denverpilot
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Keep in mind also that ADS-R as you call it, is a computer that's going to have to look at incoming lat/longs and decide what to rebroadcast on 900 MHz for airplanes with downlink capability on UAT that do NOT have Mode-S transponders and ADS-B out on 1090. It will have to decide which ground UAT transmitter to send it up through, and whether or not there are "participating" aircraft that need the traffic data within the coverage area of that transmitter. Same thing but backward for TIS.
There's a built in unavoidable delay there, and when you're talking about traffic alerts, that latency had better be very very very low.
The original engineering was to do all of this via Mode-S, direct aircraft to aircraft just like TCAS does today. The problem always was, there's not enough open airtime between real radar sweeps and heavy traffic loads to get all the transmissions in.
It's bandwidth. And all of it looks a lot like a giant erector set that is going to need some serious "smarts" on the back-end to play well. It probably can, but it's bolt on after bolt on. My experience with such systems overall in IT is that they're "brittle". They may stay up and partially work 100% of the time, but certain functionality drops out from time to time.
Whether the FDC NOTAM system can keep up with minor outages and problems is one future factor. Who can possibly read and comprehend every single FDC NOTAM for a flight with the traditional Navaid notices, and "permanent" TFRs, let alone some NOTAM that says "Inside a box bounded by W, X, Y, and Z, traffic from Mode-S airplane's will not be seen on UAT screens today..."
It's an IT system built to be completely unmanageable. Too complex, not enough built in simplicity. Convergence inside the avionics black boxes is pushing the limits on how to know the data is a) there, b) accurate, c) authentic (remember no encryption on these over-the-air data links... bad guys can spoof easily), d) timely.
We've all seen the "reminders" this week that it takes time for NEXRAD data to go from the computers that create it, to the FAA systems that aggregate it, to the private vendors that disseminate it, to our screens in the cockpit.
ADS-B as an overall system has all of these inherent problems and multiple inputs and outputs. The system managers will call the data "degraded but working" and we'll be trusting that it meets the above four criteria in little pretty colors on our PFD/MFD. It can even lull us or distract us into avoiding data we already have in our own HEADS... Two 30,000 pilots get a fancy new G1000 and start playing with it and plow right into a mountain that had been there for all of their previous 30,000 hours.
Dragging more information into the cockpit when needed, is excellent. Dragging sketchy data in, and relying on it, is deadly.
Keep in mind, we're going to have to teach these somewhat-obvious-to-us-data-geek concepts to folks who can't even send an e-mail...
Piloto
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I agree with you Nate. The rebroadcast of traffic data by the UAT ground stations may have delays or misses that are not acceptable. That's why always prefer direct plane to plane link like TCAS does. Not only TCAS updates are faster but they include the data required for RA (Resolution Advisory) and it works everywhere in the world.
José
José