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

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

#131

Post by jessriedel »

missosoup wrote: post #85
jessriedel wrote: post #82

Earlier quoted context omitted.

This may be true, but note that all the ASAT missle demonstrated to date are only capable of low-Earth orbit, just a couple thousand km from the Earth's surface. The GPS satellites operate at tens of thousands of kilometers higher altitude in medium Earth orbit. https://www.reuters.com/article/us-china-space-report/analys...

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?

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

#132

Post by capkutay »

I hope we can finally see some improvements at SFO. The fact that the slightest impact on visibility can cause 4-5 hour long delays is ridiculous. the SF government has tirelessly blocked all attempts to fix the runways so that planes can land in visibility conditions (fog/rain) with the promise that technology would solve the problem.

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

#133

Post by amluto »

tyingq wrote: post #63
BeeOnRope wrote: post #49

Earlier quoted context omitted.

Why do truckers have GPS jammers?

Beating DOT legalities, hiding things like side trips to casinos/mistresses/bars from the boss, general dislike for big brother, etc.

It should be straightforward to have GPS jammer detectors along the road. Throw in a giant federally enforced fine and people will stop using them.

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

#134

Post by briandear »

leetrout wrote: post #113
Patrick_Devine wrote: post #109

Earlier quoted context omitted.

The problem with _requiring_ authentication is that it can create a safety issue when communications break down. As a pilot it's not a bad idea to carry a spare handheld radio, or even use a cel phone, when you lose communications. I was flying once with a buddy of mine who was Pilot-In-Command and we lost (or thought we had lost) our radio on an IFR flight back into the Bay Area. What had happened was the Push-to-Ta…

Now I'm trying to remember if the radios have TX lights that would help show that you are transmitting...

G1000/G3000 radios do. TX and RX

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

#135

Post by briandear »

capkutay wrote: post #132

I hope we can finally see some improvements at SFO. The fact that the slightest impact on visibility can cause 4-5 hour long delays is ridiculous. the SF government has tirelessly blocked all attempts to fix the runways so that planes can land in visibility conditions (fog/rain) with the promise that technology would solve the problem.

The problem isn’t the airport. It’s the lateral separation requirements for IFR aircraft on the ILS. Most airliners can land in 0-0, but you can’t do 0-0 landings on parallel runways with the ILS because of lateral separation requirements.

There is also flow control that is from the FAA — under IFR the acceptance rates are reduced.

The short answer isn’t that SFO isn’t “upgraded” but the rate of aircraft acceptance is reduced under low visibility conditions per the FAA — and for good reason, separation of aircraft.

Here is more explanation: https://media.flysfo.com/media/sfo/media/weather-operations-...

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

#136

Post by l31g »

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…

In addition to the systems you mentioned, many commercial aircraft are equipped with an Inertial Navigation System[0].

[0] https://aviation.stackexchange.com/questions/43283/do-todays...

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

#138

Post by ddoolin »

leetrout wrote: post #113
Patrick_Devine wrote: post #109

Earlier quoted context omitted.

The problem with _requiring_ authentication is that it can create a safety issue when communications break down. As a pilot it's not a bad idea to carry a spare handheld radio, or even use a cel phone, when you lose communications. I was flying once with a buddy of mine who was Pilot-In-Command and we lost (or thought we had lost) our radio on an IFR flight back into the Bay Area. What had happened was the Push-to-Ta…

Now I'm trying to remember if the radios have TX lights that would help show that you are transmitting...

Yes, even many old school radios will have something that indicates transmitting or not.

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

#140

Post by madengr »

jessaustin wrote: post #125
jcrawfordor wrote: post #89

Earlier quoted context omitted.

In the US, ATC radar and military radar are one and the same - the FAA and the Air Force share the Joint Surveillance System (JSS). So, while the JSS has plenty of limitations (including plenty of areas with no coverage even in the mainland US), it's designed to meet the military objectives of being able to locate even non-cooperating aircraft. The JSS is a descendant of the SAGE system developed during the Cold War…

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

Is that in MO? There is a similar one near Belton. I believe it is C band radar. The FCC database should have it.
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