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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

#61

Post by [deleted] »

throw0101a wrote: post #47
MereInterest wrote: post #22

There was a talk at DEFCON about this in 2012 [1]. The main issue is a radar system gets its information from ground-based measurements, while a GPS system gets its information from air-based measurements that are later transmitted to the ground station. This means that those reports can be spoofed, or lied about, or absent entirely. https://www.youtube.com/watch?v=CXv1j3GbgLk

The validity of location data can be verified by cross checking where the plane claims it is, and where the signal is detected to be, via MLAT: * https://en.wikipedia.org/wiki/Multilateration * https://www.radartutorial.eu/02.basics/rp52.en.html * http://www.multilateration.com/surveillance/multilateration.... This can further be cross checking with space-based systems like Nav Canada's: * https://en.wikipedia.org/wi…

[deleted]

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

#62

Post by mft_ »

burundi_coffee wrote: post #56
BeeOnRope wrote: post #49

Earlier quoted context omitted.

Why do truckers have GPS jammers?

You either didn't see the comma or you're joking

Don’t think they’re wrong in their interpretation. Why would a trucker without a GPS jammer driving by an airport cause an issue?

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

#63

Post by tyingq »

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?

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

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

#64

Post by cmurf »

code4tee wrote: post #14

Radar isn’t going away. This article talks as if ADS-B is replacing radar, which it’s not. It’s enhancing radar where radar coverage exists and providing coverage on traffic where radar coverage currently does not exist (usually lower altitudes away from major airports and over the ocean).

ADS-B and Mode A/C/S (MSSR) are both secondary radar. but the equipment differs, in particular the ground equipment looks different. It could be that the MSSR equipment gets phased out as ADS-B prevails. Primary radar will continue to be used though, in particular at airports (ones other than the many local uncontrolled variety).

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

#65

Post by Merrill »

>GPS JAMMING EXPECTED IN SOUTHEAST DURING MILITARY EXERCISE

>GPS reception may be unavailable or unreliable over a large portion of the southeastern states and the Caribbean during offshore military exercises scheduled between January 16 and 24.

https://www.aopa.org/news-and-media/all-news/2020/january/14...

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

#66

Post by throw0101a »

o-__-o wrote: post #9
mattlutze wrote: post #3

If there's anyone in the air control technology industry here, I'm curious what parts of this change get you really excited, and which parts get you really nervous?

The cost. This affects general aviation as older planes will require avionics upgrades. Otherwise I’m excited for the sheer amount of data that will be made available to the public. Now you will be able to track all FAA registered planes

> Now you will be able to track all FAA registered planes

Almost all.

If you're flying VFR you can put your transponder into an anonymous / incognito mode (if it supports it):

* https://www.avweb.com/aviation-news/faa-acts-to-preserve-ads...

If you want IFR or flight following you'll have to de-anonymized, which is no worse than it was before ADS-B.

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

#67

Post by jrockway »

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 radar and secondary radar in addition to ADS-B information.

You could probably cause a lot more trouble by 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.

Ultimately the system comes down to many systems working together, not one stream of commands between two computers.

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

#68

Post by ceejayoz »

Someone wrote: post #24
knodi123 wrote: post #12

Earlier quoted context omitted.

I took flight school a few years ago, and had to learn to tune in non-directional radio beacons, and use VHF Omni-Directional Range tools for navigation. I wasn't allowed to use the GPS until I demonstrated mastery of the others. Considering that, I suspect the aviation industry will keep both systems working for a surprisingly long time.

This isn’t for pilots to know where they are, it’s for air traffic control to know where planes are. If GPS were to become the sole way to do the latter, every airplane would effectively get an invisibility cloak that those who want to do evil can activate (and even worse. Switching off the on-board transmitter is less scary than spoofing signals) Because of that, I would expect they keep using some way to detect pla…

> If GPS were to become the sole way to do the latter, every airplane would effectively get an invisibility cloak that those who want to do evil can activate...

This is already the case. Much of the civilian radar system already relies on transponders to get a good fix on aircraft, via secondary radar. Primary radar coverage (no transponder required) is much more limited. Turn off the transponder and you'll largely disappear from ATC's screens.

ADS-B isn't new in this regard.

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

#69

Post by AviationAtom »

vijayr02 wrote: post #57
BeeOnRope wrote: post #49

Earlier quoted context omitted.

Why do truckers have GPS jammers?

https://gizmodo.com/jamming-gps-signals-is-illegal-dangerous... > he’s seen truckers trying to avoid paying highway tolls, employees blocking their bosses from tracking their cars, high school kids using them to fly drones in a restricted area, and even, he believes, undercover police officers using them to avoid tails

Don't forget the Kremlin spoofing the local airport to try to keep drones from flying near their government buildings!

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

#70

Post by throw0101a »

coldcode wrote: post #5

The same GPS the US Government reserves the right to reduce the precision when they feel like it? Seems risky idea to assume they will never do this.

> reduce the precision

GPS satellites will not have the hardware to do selective availability in GPS III, which are currently being launched:

* https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_...

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