Which makes you wonder why they don't configure adsb ground stations to trigger off something other than just adsb-out radio signals, to enable the 'hockey puck' that you're flying in. If they did that you could see stuff thats in the ATC radar system without having to have an adsb-out plane within the 'hockey puck'. But I guess as more get rolled out the pucks will be live more than not and the eavesdroppers may benefit more.
Why couldn't your non-adsb transponder trigger it? They're just being stingy or trying to force compliance to get the full benefits, I guess. The primary reasoning I guess was to keep radio traffic down when not in use by a 'legit' receiver.
It COULD have been set up this way. The reality is, the "puck" is horse-puck-ey designed to make the system LESS SAFE in order to force uptake. A great idea from an agency that claims to want safety, eh?
There is no damned technical reason a Mode C aircraft with a cheap ADS-B IN couldn't have 99% of the feature set of ADS-B and never need a Mode-S transponder or UAT transmitter. Ever. No need for it at all. The need is generated by the puck.
I don't know how to get this technical FACT into people's heads. The FAA purposely crippled a safety system to push an $8B agenda. Yes, it's really that simple.
The reality is, this is about SURVEILLANCE and never ever ever was really about safety. Otherwise the "puck" would not exist.
The NexGen system is complex and is based on a combination of specialized aircraft equipment (WAAS GPS, transponders, and processing units), ground stations, and GPS sats (there will be 61 NextGen sats launched). ADS-B is not radar.
ADS-B Out works by transmitting information about an aircraft's location, ground speed and other data to satellites once per second. This information is simultaneously beamed back down from the sats to a network of ground stations. ADS-B "in" equipped aircraft can receive and process the information for enhanced situation awareness. ATC will also have this data available to them. ADS-B ground stations will also transmit other data products like FIS-B Nexrad weather free of charge.
Uhh. No. Would you like me to get the guy I know who's installing the ground stations (and also works on radar systems) for FAA Operations to explain to your dumb ass that ALL of his ADS-B ground stations are fed with copper or fiber?
It's a bandwidth limitation AND more importantly a TIME limitation. This is Telecom data engineering 101.
Do you know what the round trip time to even LEO is? How about geosynchronous orbits? You CAN NOT process position data fast enough in the terminal environment with a satellite round-trip-time, plus buffering for error correction, plus processing time (have to slow it all down to see who's got a PUCK you know!), plus retransmission time on both Mode-S and UAT.
The system ALREADY has trouble making the spec for delay from reception to retransmission in high density traffic areas, this is how we got UAT!
And you think they're sending it to a SATELLITE!? Beat. Head. Here.
The satellite portion of ADS-B is a completely unrelated animal intended to track OCEANIC aircraft and aircraft not in reach of a ground station. It's the world's response to Malaysia Air.
It is NOT fast enough or even CLOSE to fast enough to be used in the lower separation of terminal environments.
No human scan can come close to ADS-B. The system is also the basis of GPS replacing radio based ILS and VORs nationwide. By 2020 the FAA says all ARTCC/TRACON and 160k aircraft will be on the system. And all B, C and D fields will have precision GPS IAPs.
ADS-B has ABSOLUTELY NOTHING TO DO WITH GPS APPROACHES OR VOR SHUTDOWNS. It is not the "basis" for it. It provides ZERO benefit to navigation.
FAA has clearly announced that radar will STILL BE PRIMARY for ATC in terminal areas, period, full stop, no plans to remove it, zip, nada, zilch. NO ADS-B required at ALL.
It is a SECONDARY ONLY system only after being certified in an area to be used in combined data. And it is not ever required for a GPS approach or any navigation purpose.
It also has been made clear that it offers controllers NO ADDITIONAL SEPARATION between aircraft. Even the FedEx trial did NOT allow it at MEM.
Much more efficient to say "bug destroyer 666. request VFR advisories"
Then you can keep your eyes outside, you won't drain the batteries on your iJunk, and you'll hear the controller talking to the other guy and you so there is no mystery.
What? We have a system that doesn't cost an additional $8 BILLION DOLLARS that works? Holy hell. Why didn't someone tell us sooner? LOL.
ALL... of the safety features of ADS-B for traffic could have been done with wide area multi-lateralization (simple fixed ground stations that can replace primary radar extremely cost effectively - already deployed in the Aspen valley for years, by the way) and a single UAT *style* data uplink transmitter that doesn't discriminate -- it has no "puck" -- and sends up all traffic to all in its coverage area. Easily 1/10th or less the price of ADS-B. Those same transmitters could have included the weather data.
"Free" as they say. Well a lot less than $8 billion with a B.
ADS-B is about one thing. The Mode-S or UAT individual aircraft ID code. It's surveillance. Everything it does could have been done cheaper and just as well with all ground-based tech -- tech already operational and certified into the system. No change of equipment on board any Mode-C equipped aircraft, required.
By the way, multi-lateralization is awesome stuff. There's already a 250W transponder (or higher for the high altitude folks) on board, and measuring the time of reception after triggering it, at multiple ground locations, with simple vertical antennas, is incredibly cheap, efficient, and accurate. The only real reason for primary spinning radars, is DoD. Secondary radar done by nothing but a small box with a decent clock reference and a vertical antenna on a telephone pole, replaces everything needed for air traffic control that comes from a primary aircraft radar other than emergency use -- to spot an aircraft that's lost on board power.
And ADS-B, multilaterizarion, Mode-anything, other than primary skin paint, doesn't work for that. Same thing with unknown targets... smugglers, war, whatever... primary is used for those.
ATC? Transponders were and are, a very elegant way to handle that. Hit it with RF, it responds nearly instantly. 250W of location pegging RF coming back at'cha. Done.
You HAVE to know how this stuff works, to know when you've been snowed by marketing BS. I've been doing the RF and terrestrial data biz for a very long time. Nothing about ADS-B is about safety, and nothing about it is about providing safety at the best possible cost.
"NexGen" is even more hilarious. What "Gen" are they shooting for? The late 1990s? LOL. Because that's where most of this tech falls on the tech timeline.
