Earth shattering news: UK CAA says GPS is a Good Thing

There is a real difference between gps being completly off versus wrong but sensible reading, as pilot who relies on GPS, I am more scared of the later and I prefer to see a red flag

For widspread jamming of GPS, you will probably need a full constellation up in the sky while for radio/radar stuff well: good luck, the technology is quit proven and people try to hack it in cold war without much sucess due to simple physics you mentioned (you need a lot of signal grid & power to cover space/time and all wavelengths, such infrastructure will not go unoticed and for sure you can’t fit it in a truck)

Ibra wrote:

If someone is able to jam GPS on large scale, I don’t see what will prevent them from doing the same with a VOR/ILS/DME?

Physics.

The GPS signal is at best -125dBm, which is around 3.2 × 10E-16 (0.32 Femtowatt, 0.00032 Picowatt). This is what is left over after travelling all the way down from the 20,000 km orbit, where it is transmitted with around 50W (times antenna gain)

Any jamming signal on earth or carried by a small drone a few miles up is much, much, stronger. Now, GPS jamming is not quite as easy as blaring in the GPS spectrum, but it should be pretty obvious that it does not require much power to cover a large area.

Also, geometry. To generate a signal at the receiver that is much stronger than the one you want to jam, it helps if you are closer to receiver than the transmitter. For a GPS, that basically means “being on Earth, with line of sight to the aircraft”, while for the ILS/VOR it means “being close to the aircraft”

The ILS and VOR signals are much stronger and more local. While the receivers are of course a lot less sensitive and work in a completely different way, and jamming is actually easier if you have the power, widespread jamming is next to implossible, and would require many, many transmitters (or a HUGE one high up)

If someone is able to jam GPS on large scale, I don’t see what will prevent them from doing the same with a VOR/ILS/DME?

Then you are left with compass/watch or sun/stars (for the brave) as “safe alternatives” but honestly how much they are useful?

Even if all cockpit navs fails, you still have VDF/radar fixes which you can use before reverting to “stars catalogues” and “real pilot nav skills”, while GPS/LPV and VOR/ILS may seem redundant, personally, I think you can do with just one of them but you need ATC backup…

Only lost GPS signal once, late 90’s IFR to Zagreb when there were still some NATO restrictions. Am guessing NATO were degrading signal/jamming. Zagreb radar asked for a maximum speed ILS as there were two MIG-21s behind.

Well, we did have several incidents of Russian jamming in Northern Norway the last year. It could last for weeks, and made every single GPS useless, not just aviation GPS’es, although they were effected most due to the jamming signals (or whatever it is) reaching them better. If SAS and Widerøe had been 100% reliant of GPS, they couldn’t fly there.

It’s still some time before maps, compass and VOR/ILS/DME is completely redundant.

MGL recently announced their (non-certified) NAV receiver.

The UK CAA has come a long way in a short time in terms of embracing new technology unlike some other EASA states who seem to wedded to certification rules and unable to think in a pragmatic way. However it’s not just the authorities that are to blame, a lot of people in maintenance business are very inflexible resulting in new technology not being fitted. The new traffic systems are a classic item of misunderstanding with people not integrating them with aircraft systems because of perceived or misunderstood certification issues.

As for iPad gps performance, mine seems to work just as well as the systems fitted to Mr Boeing’s finest, instatll Jepp flight deck and put the flight plan in and you get all sorts of useful data and airspace warnings.

Archie wrote:

but at the same time you can’t use it on your flight test!!!

Do you mean SkyDemon to navigate or JeppFD to get your plates?

Peter wrote:

we seem to be a long way from it being used in the PPL as the primary nav tool, which is what the original link claimed.

The CAA here (CASA) is tiptoeing into this area being gun shy at the same time i.e. they are keen for flight schools to include EFB into their curriculum, but at the same time you can’t use it on your flight test!!!

Pavel wrote:

The time base of the SPGs is synchronized by using GPS receivers.
Recently some of their units started behaving erraticaly, sometimes, somewhere.
They realized that Japan has launched satellites called Quasi-Zenith Satellite System. Signal of these satellites interferes with the GPS signal and can cause the GPS receiver to unlock.

Japan’s QZSS is their local SBAS for Navstar GPS, so frankly I’m surprised it makes GPS reception worse (!)