Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

wsj.com

Post reply on HN
Print view View original

91–100 of 197 posts

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#91

Post by jcrawfordor »

adatavizguy wrote: post #19
yingw787 wrote: post #8

To an extent, this sounds terrifying. The first thing that jumped to my mind is that GPS be jammed or spoofed. In fact, the U.S. military in its shift away from COIN to great power competition in possibly highly contested environments is training to have less reliance on GPS: https://www.zerohedge.com/news/2018-01-26/usaf-begins-massiv... Radar can be jammed too, but I would guess the EM signature powerful enough to…

We still maintain Loran C[0]. Interesting to note receivers have been developed to grab the radio signal from all available stations, up to 40, and triangulate location with eLoran. It's a nice to have as backup to GPS however I'm not sure if it is effective against jamming or spoofing. So, the navy still teaches celestial navigation to officers. [1] EDIT: Apparently Loran C was discontinued in 2010. [0] https://en.w…

Loran-C has been discontinued. However, there are occasional ongoing proposals to restore it as "eLORAN" using newer digital transmitting and receiving equipment, to provide a terrestrial backup for GNSS. These have mostly fallen flat for simple funding reasons, but increasing attention to ASAT warfare keeps discussions going.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#92

Post by JoeAltmaier »

JoeAltmaier wrote: post #53

Lots of important cautions posted in this thread. On the plus side, lots of opportunity to create cockpit displays, warning devices etc to increase pilot safety!

Really! I'm working a contract on a cockpit device now, for this new requirement.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#93

Post by jcrawfordor »

onepremise wrote: post #44

I worked for a firm, which studied satellite navigation and implementation for air traffic control, guidance, safety, and ILS. I don't think that will ever happen. There are huge gaping issues with GPS, both WAAS and GBAS. It's very unreliable, especially in bad weather. The old-school RF tower and ILS, which used Carrier frequency pairings by the runway, are way more reliable and propagate bad weather while guiding…

The ATC scenario has significantly more relaxed requirements than ILS, and this change is intended primarily to provide coverage in situations where there is no, or limited, coverage from conventional methods (primary/secondary radar), and likely ultimately to replace the outdated secondary radar system with a space-based one.

ADS-B is not a guidance tool and will not lead to any more usage of GPS for guidance than is currently common - and certainly won't impact ILS. They're just totally different use-cases.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#94

Post by korethr »

FabHK wrote: post #76
jrockway wrote: post #67

A lot of comments seem to be about spoofing. Remember that there are multiple humans in the loop -- experienced pilots and experienced air traffic controllers -- and multiple levels of redundancy. Pilots have access to barometric altitude, radar altitude, traditional VHF navaids, TCAS-issued resolution advisories (based on directional antennas, not GPS)... in addition to GPS. Air traffic controllers have primary rada…

> buying an aviation radio off the shelf and just chatting on the frequency or issuing fake clearances if you want to be a mass murderer Incidentally, I am happily surprised that that never seems to happen. One could so easily create so much chaos at an airport... There is no authentication whatsoever.

I'm kind of wondering if there even needs to be. If you keyed up on frequency near a major airport as described in the GP, I'm pretty sure the FAA and FCC would be working together to track you down in short order. I could see the argument that it would be good to add authentication to the radios to complement the strict enforcement for a sort of belt-and-suspenders approach. However, I think a more pressing concern for aviation radio is that is is kept simpler, and thus with fewer failure modes, and thus more reliable Because when you need that radio in an emergency, that has to be the worst possible time to have to deal with authentication hiccups.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#95

Post by aidenn0 »

jaywalk wrote: post #77
onepremise wrote: post #44

I worked for a firm, which studied satellite navigation and implementation for air traffic control, guidance, safety, and ILS. I don't think that will ever happen. There are huge gaping issues with GPS, both WAAS and GBAS. It's very unreliable, especially in bad weather. The old-school RF tower and ILS, which used Carrier frequency pairings by the runway, are way more reliable and propagate bad weather while guiding…

> Even the GPS signal itself has latency and lag What do you mean by this? You sound pretty knowledgeable, so you must know that it's simply not possible for the GPS signal to have latency or lag.

Not the poster, but while the GPS signal doesn't have lag, many receivers run the output through a Kalman filter for higher precision.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#96

Post by vkou »

voxl wrote: post #83
qrbLPHiKpiux wrote: post #79

Earlier quoted context omitted.

But the risks and consequences are catastrophic. The Feds will put you away forever for even attempting it.

While true, you'd think state sponsored terrorism wouldn't care about sacrificing a few people.

What kind of state sponsored terrorism? Black ops programs? Air forces dropping bombs? Assassinations and decapitation strikes?

Or are we talking about the boogieman that is an excuse for all sorts of paranoid crackdowns, expenditures, and questionable legislature?

Who exactly are you afraid will sponsor radio jammers at airports, and why do you think they will do so?

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#97

Post by simonswords82 »

mc32 wrote: post #37
simonswords82 wrote: post #31

Earlier quoted context omitted.

They simply won't turn their GPS on.

Won’t they have to before takeoff? Or will that not be a requirement?

They'll ignore the rules as I'm sure they already do.

As you'll see from the various documentaries, historically planes operating illegally and/or doing illegal things will fly "under the radar" and keep their transponder turned off to evade the authorities.

They'll do the same thing with GPS.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#98

Post by LargoLasskhyfv »

korethr wrote: post #94
FabHK wrote: post #76

Earlier quoted context omitted.

> buying an aviation radio off the shelf and just chatting on the frequency or issuing fake clearances if you want to be a mass murderer Incidentally, I am happily surprised that that never seems to happen. One could so easily create so much chaos at an airport... There is no authentication whatsoever.

I'm kind of wondering if there even needs to be. If you keyed up on frequency near a major airport as described in the GP, I'm pretty sure the FAA and FCC would be working together to track you down in short order. I could see the argument that it would be good to add authentication to the radios to complement the strict enforcement for a sort of belt-and-suspenders approach. However, I think a more pressing concern…

Could they? A moving target? Say the soundproofed back of some van.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#99

Post by myself248 »

BeeOnRope wrote: post #49
onepremise wrote: post #44

I worked for a firm, which studied satellite navigation and implementation for air traffic control, guidance, safety, and ILS. I don't think that will ever happen. There are huge gaping issues with GPS, both WAAS and GBAS. It's very unreliable, especially in bad weather. The old-school RF tower and ILS, which used Carrier frequency pairings by the runway, are way more reliable and propagate bad weather while guiding…

Why do truckers have GPS jammers?

So their corporate telemetry system doesn't document their long lunch at the strip club which, for other reasons, happens to be located just around the corner from the airport.

Re: Air-Traffic Control Is in the Midst of a Major Change from Radar to GPS

#100

Post by sokoloff »

gryphonshafer wrote: post #52

A valuable part of the ADS-B out mandate is that planes even as small as mine (a.k.a. tiny) can cheaply (<200$US) pick up ADS-B in and display it on a consumer tablet. My private airplanes now have pseudo radar. Not every airplane in the air is broadcasting, but most are. This is a huge safety win. Almost without exception I'll see airplanes on my tablet long before I have visual on them.

Without ADS-B out on your airplane (which you don't have for https://ipadpilotnews.com/2019/09/ads-b-traffic-when-does-it...

https://www.faa.gov/nextgen/programs/adsb/faq/#x8 You probably have a much large hole in your coverage than you thought.

Post reply on HN