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

181–190 of 197 posts

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

#181

Post by danaliv »

lutorm wrote: post #163
danaliv wrote: post #130

Earlier quoted context omitted.

Indeed. Not everyone even has to have ADS-B Out. You only need it if you’re going into or over Class C or B airspace, in the Class B veils, Class E above 10,000 except below 2500 AGL, and in Class E over the Gulf of Mexico. That leaves huge swathes of airspace—dare I say most airspace in the US—where ADS-B isn’t required. You could fly across the entire country without hitting an ADS-B requirement. And the only way f…

Except that is also the same airspace where ATC doesn't have to see you. You don't even need a transponder to fly in those areas.

It’s not just about seeing you, it’s about seeing everyone around you too. ATC’s job is to separate aircraft and they can’t do that if they can’t see non-ADS-B aircraft. In fact just today I overheard an approach controller vector an American Airlines jet around VFR traffic at 1700’. That VFR traffic was in “non-rule” airspace, where ADS-B isn’t required. (I saw the jet and the VFR traffic from my cockpit.) They won’t be able to do that without radar.

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

#182

Post by dragonwriter »

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.

With state sponsored terrorism, the risk isn't that the Feds will put the agent away forever, it's that the USG (and, incidentally, other particularly allowed countries) will identify that it is state sponsored terrorism and treat the attack as exactly what it is—simultaneously and act of war and a gross violation of the laws of war.

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

#183

Post by missosoup »

jessriedel wrote: post #131
missosoup wrote: post #85

Earlier quoted context omitted.

Demonstrating ASAT against a GEO target would cause a major political incident. The LEO ASAT tests carried out to date caused enough outcry as is. Hitting a GEO target is not difficult. Ignoring dedicated ASAT missiles, any modern IRBM or LRBM can be tasked to intercept a GEO target. Global navigation constellations are certainly going to be one of the first targets in any major hot conflict between world powers. Rea…

> Hitting a GEO target is not difficult. Ignoring dedicated ASAT missiles, any modern IRBM or LRBM can be tasked to intercept a GEO target. Do you have a cite for this?

Not as an overt blanket capability statement, but e.g. LGM-30 is known to carry ASIP and rumoured to carry THAAD kill vehicles, both capable of intercepting dynamic orbital targets. LGM-30 climbs to 100km altitude before deploying the payload bus, which gives it ample range to hit GEO targets anywhere in the hemisphere.

Other thing I completely forgot to mention is that all existing global navigation constellations orbit at MEO, not GEO. Which puts them within speculative range of demonstrated ASAT weapons and allows for even longer reach from a launch vehicle like LGM-30.

https://www.mda.mil/news/11news0002.html

https://www.raytheon.com/capabilities/products/ekv

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

#184

Post by Piskvorrr »

iudqnolq wrote: post #171
toomanybeersies wrote: post #162

Earlier quoted context omitted.

General aviation flies a lot lower and slower than passenger jets.

I've accidentally had phones on during takeoff and they lost signal within seconds. Were they already going too fast? Or was there jamming?

Moving too fast for the cell network to keep up, I'm guessing. Before it manages to handoff to the next cell, you're actually leaving that one already.

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

#185

Post by Piskvorrr »

asteli wrote: post #153
echelon wrote: post #141

Earlier quoted context omitted.

Imagine an unlicensed drone emitting GPS radio signals. Just a small amount of sophistication and an attacker can do an incredible amount of harm.

If you live in Florida, you can go down to the pawn shop, buy a gun, drive over to the airport and start shooting at planes. Doesn't take much sophistication to cause a lot of harm.

At a plane. Then you get a SWAT response and terrorism charges - consequences are also a reason this doesn't happen on a mass scale.

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

#186

Post by serf »

sokoloff wrote: post #172
FabHK wrote: post #169

Earlier quoted context omitted.

Nice plane you have, if you fly above 10000' or above 150 knots frequently :-)

I've upgraded since, but my old 182 would do 10K any day and 150knots with a slight tailwind.

did it have the retractable gear? I've always loved that design.

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

#187

Post by sokoloff »

serf wrote: post #186
sokoloff wrote: post #172

Earlier quoted context omitted.

I've upgraded since, but my old 182 would do 10K any day and 150knots with a slight tailwind.

did it have the retractable gear? I've always loved that design.

No, mine was a straight 182. I agree that the 182RG is a great airplane.

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

#188

Post by jessriedel »

missosoup wrote: post #183
jessriedel wrote: post #131

Earlier quoted context omitted.

> Hitting a GEO target is not difficult. Ignoring dedicated ASAT missiles, any modern IRBM or LRBM can be tasked to intercept a GEO target. Do you have a cite for this?

Not as an overt blanket capability statement, but e.g. LGM-30 is known to carry ASIP and rumoured to carry THAAD kill vehicles, both capable of intercepting dynamic orbital targets. LGM-30 climbs to 100km altitude before deploying the payload bus, which gives it ample range to hit GEO targets anywhere in the hemisphere. Other thing I completely forgot to mention is that all existing global navigation constellations o…

> LGM-30 climbs to 100km altitude before deploying the payload bus, which gives it ample range to hit GEO targets anywhere in the hemisphere.

This doesn't make sense to me. Could you explain further? LGM-30 is a land-based ICBM designed to strike targets on the surface of the Earth, and hence to take a (just barely) sub-orbital trajectory altitude, where MEO satellites like GPS are?

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

#189

Post by missosoup »

jessriedel wrote: post #188
missosoup wrote: post #183

Earlier quoted context omitted.

Not as an overt blanket capability statement, but e.g. LGM-30 is known to carry ASIP and rumoured to carry THAAD kill vehicles, both capable of intercepting dynamic orbital targets. LGM-30 climbs to 100km altitude before deploying the payload bus, which gives it ample range to hit GEO targets anywhere in the hemisphere. Other thing I completely forgot to mention is that all existing global navigation constellations o…

> LGM-30 climbs to 100km altitude before deploying the payload bus, which gives it ample range to hit GEO targets anywhere in the hemisphere. This doesn't make sense to me. Could you explain further? LGM-30 is a land-based ICBM designed to strike targets on the surface of the Earth, and hence to take a (just barely) sub-orbital trajectory altitude , where MEO satellites like GPS are?

It takes about 0.6 tons of fuel to transfer from a 100km to a 20,000km orbit. Well within the payload limits of LGM-30.

A derivative of the LGM-30, Minotaur, is used to launch satellites (or ordnance) directly to GTO @ ~30,000km.

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

#190

Post by jessaustin »

jcrawfordor wrote: post #144
jessaustin wrote: post #125

Earlier quoted context omitted.

Is there any other entity that operates these sorts of radomes? On a regular commute of mine, there is one owned by the federal government that has no sign out front [0], but it's not listed on the JSS page [1]. [0] https://goo.gl/maps/KHTP7vruKvGyqQu66 [1] https://en.wikipedia.org/wiki/Joint_Surveillance_System

It took a bit of digging... this is an FAA radar, but not JSS. It's a secondary radar reporting to the Kansas City ARTCC, code ZQJN. Essentially, it transmits an 'interrogate' message in response to which aircraft transponders transmit information on the aircraft. This is the system that ADS-B is more or less a direct upgrade from. I'm not sure exactly what equipment is installed there, I found an older report listin…

You're very knowledgeable! I've been curious about this for a while. The site and equipment does seem well maintained, so I don't think it has been retired yet.
Post reply on HN