ADS-B Prediction

Ground stations are supposed to be done by 2013. Right now you've got coverage on the East Coast, and in the "Sunbelt" WTF that is. I'd bet you'd have coverage to Atlanta.

It looks to me like the way to equip an airplane is with 1090ES out and add a UAT receiver to get the FIS and TIS data. I still can't wrap my head around the dual standards - it seems stupid to me.
 
TMetzinger said:
Ground stations are supposed to be done by 2013. Right now you've got coverage on the East Coast, and in the "Sunbelt" WTF that is. I'd bet you'd have coverage to Atlanta.

It looks to me like the way to equip an airplane is with 1090ES out and add a UAT receiver to get the FIS and TIS data. I still can't wrap my head around the dual standards - it seems stupid to me.
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comment banished to the SZ (smile)
 
TMetzinger said:
Ground stations are supposed to be done by 2013. Right now you've got coverage on the East Coast, and in the "Sunbelt" WTF that is. I'd bet you'd have coverage to Atlanta.

It looks to me like the way to equip an airplane is with 1090ES out and add a UAT receiver to get the FIS and TIS data. I still can't wrap my head around the dual standards - it seems stupid to me.
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If it can be tied into TCAS then 1090ES makes sense for heavy iron. ES is allowable for operations below FL180, so that can work for us little guys. For lower altitude operation in radar "holes" (which don't much exist high up), UAT will allow inexpensive ground stations.

It all makes sense in a government sort of way.

NavWorx makes a "portable" UAT receiver that will interface with some portable in-flight nav packages. I don't see ForeFlight listed, however.
 
But in order for "real" don't-hit-anything coverage everywhere, every airplane would need to be outputting 1090ES and listening for it too, whether they have TCAS or not. You won't get the TIS-B stuff outside of UAT ground stations, and they won't have complete coverage.

Really, what airplanes need a box that responds to radar, transmits and listens on 1090ES (whether it then feeds a certified TCAS or just a TIS-like traffic display), and listens on UAT (978) for FIS-B stuff. And it should cost no more than a current ModeS transponder and XM-WX datalink. Then you just feed all the data to whatever systems you have for display.

go one step further and require a C146 WAAS receiver in the ADS-B unibox, and feed THAT data to the ADS-B output, and to a separate FMS which is like a 430/530 without the GPS receiver portion.

Ditch UAT-out from airplanes altogether, and save the need to rebroadcast. Everybody uses 1090ES for position output and collision avoidance, and 978 is just for data link (Wx, TFR, Clearances, In-flight Advisories, etc).
 
You're VFR, so um....................use your eyeballs?
 
Tim,

Just reading between the lines on some FAA publications, I believe the dual standard exist because:

TCAS II recieves on 1090 and transmitts on 1030, Mode S Transponders recieve on 1030 and transmit on 1090.

They want ADS-B, but they don't want to saturate 1090MHz with too much traffic, so all those aircraft not using TCAS II use UAT.

TCAS is recognized as a safety necessity.

TCAS II w/1090MHz XPDRs is in place, it works, there is no ready replacement TCAS for use in other frequency bands.

There is a spec out there for Hybrid TCAS (ADS-B GPS based TCAS) but it's very new.
 
I don't know why everyone gets so hung up about the TCAS element or it ? Free nexrad is all I care about ! Why be a slave to the idiots at XM forever ? You've ALREADY paid for it with your tax dollars, its out there why not get a box that lets you use it ? www.navworx.com
 
kontiki said:
Tim,

They want ADS-B, but they don't want to saturate 1090MHz with too much traffic, so all those aircraft not using TCAS II use UAT.

TCAS is recognized as a safety necessity.
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Problem is they don't do anything to prevent the saturation of 1090 since lots and lots of airplanes (GA) already have Mode S. Pretty much all the G1000 airplanes, plus those in the last fifteen years who got Mode-S for the TIS on their MFDs, and all the big GA airplanes who have TCAS.

So I can foresee pretty much all the airplanes using 1090ES for the output.
 
EdFred said:
You're VFR, so um....................use your eyeballs?
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Notoriously unreliable devices. Narrow field of view requires considerable scanning to compensate, but the scanning stepper motors tire out quickly. They also often lose focus. Objects on intercept will appear stationary to these devices, but have no means to detect the changing distance; only clue to closing is change in subtended arc of closing object.

And these devices are already task overloaded at critical moments where traffic is highest.

All that said, the risk of mid-air collisions is very low. If given only a choice between looking for traffic before downwind-to-base or base-to-final turns and looking at your airspeed indicator, accident statistics support the conclusion that you'd be better served checking your airspeed.
 
There's nothing wrong with using all the help you can get spotting traffic, and no reason you have to rely exclusively on the Mark I eyeballs. I can't begin to count the number of times that TIS-B has made me aware of traffic that I would not have seen with my Mark I's, possibly until it was too late (though as Jim L says, in most cases there never would have been a collision anyway).

That said, there have been lots of targets called out to me by ATC that didn't show up at all on TIS-B. I'm not sure which targets get sent and which don't, though it's certainly not as simple as that only "ADS-B out" equipped traffic shows up, since I know from the symbol shape that most (actually nearly all, better than 99%) of the targets I see are just ordinary Mode C equipped aircraft. Anyway, if I had to choose only one extra pair of eyes, ATC or TIS-B, I'd choose ATC... but TIS-B is a very nice extra to have.
 
Jim Logajan said:
Notoriously unreliable devices. Narrow field of view requires considerable scanning to compensate, but the scanning stepper motors tire out quickly. They also often lose focus. Objects on intercept will appear stationary to these devices, but have no means to detect the changing distance; only clue to closing is change in subtended arc of closing object.

And these devices are already task overloaded at critical moments where traffic is highest.

All that said, the risk of mid-air collisions is very low. If given only a choice between looking for traffic before downwind-to-base or base-to-final turns and looking at your airspeed indicator, accident statistics support the conclusion that you'd be better served checking your airspeed.
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For traffic avoidance sure, but if you can't see a thunderhead building while VFR you either 1) aren't VFR, or 2) shouldn't be flying because you are waaaaaaay worse than 20/40 as required by the Class III medical. He was asking about the weather, not the traffic portion of it, and that's what I was addressing.
 
wsuffa said:
NavWorx makes a "portable" UAT receiver that will interface with some portable in-flight nav packages. I don't see ForeFlight listed, however.
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Their receiver doesn't appear to be compatible with the iPad at all.

SkyRadar has one, but it's kinda pricey.
 
EdFred said:
For traffic avoidance sure, but if you can't see a thunderhead building while VFR you either 1) aren't VFR, or 2) shouldn't be flying because you are waaaaaaay worse than 20/40 as required by the Class III medical. He was asking about the weather, not the traffic portion of it, and that's what I was addressing.
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Dang straight I'm using my eyes. At the speed I'm going and a 12min potential refresh rate, I will be right on a TRSA if I'm head down.
 
flyingcheesehead said:
Their receiver doesn't appear to be compatible with the iPad at all.

SkyRadar has one, but it's kinda pricey.
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Neither was the WxWorx weather box.... until Baron decided to/got pressured to make an interface. (hint, hint).

Or perhaps if Apple used some other kinds of interface, like Wintel boxes can.... :rolleyes:
 
EdFred said:
For traffic avoidance sure, but if you can't see a thunderhead building while VFR you either 1) aren't VFR, or 2) shouldn't be flying because you are waaaaaaay worse than 20/40 as required by the Class III medical. He was asking about the weather, not the traffic portion of it, and that's what I was addressing.
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OK. There was a mix of TCAS and WX references; guess I picked up on the wrong aspect.

Agreed that for VFR your eyes are just fine for weather avoidance for most conditions.
 
Yeah, the traffic avoidance is great, but you can get that solved for under $1500 and not worry about ADS-B.
 
wsuffa said:
Neither was the WxWorx weather box.... until Baron decided to/got pressured to make an interface. (hint, hint).

Or perhaps if Apple used some other kinds of interface, like Wintel boxes can.... :rolleyes:
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Like Bluetooth? :devil:
 
kontiki said:
They want ADS-B, but they don't want to saturate 1090MHz with too much traffic, so all those aircraft not using TCAS II use UAT.
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Any idea of how many it would take to saturate it? I'm just curious; I haven't read any of the specs...
 
TCAS II (Minimum Operational Performance Specifications in DO-185) is mandated for specific classes of airplanes. I think for AC over 33, 000 lbs gross wt or carrying more than 19 passengers.

For TCAS II to work, each aircraft must be equipped with a TCAS II processor and at least one Mode S Transponder.

I don't know of any other reasons for equipping an aircraft with a Mode S transponder, but there may be some.

There has been work on increacing data capacity on 1090 Mhz try googling on 1090 MHz overlay.
 
kontiki said:
I don't know of any other reasons for equipping an aircraft with a Mode S transponder, but there may be some.
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TIS datalink where available. Not sure of the mechanics, but in SOME tracons I've found that Mode S is acknowledged much faster than Mode C.
 
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