In north-western parts of Norway, GPS is down every now and then due to Russian jamming. It has been going on for years. Record high at the end of last year with jamming 1 out of 3 days. The funny thing is it doesn’t affect aviation (cat), but everything else 
The backup is the old system (DME/VOR/NDB).
I’m not so sure there exists any pan European plan. Maybe there are some papers, but not any plan that is put into effect. Avinor just finished their WAM system this spring. This is of course equivalent to radar, but much better coverage, higher accuracy and works just as good for VFR. In principle, I don’t see why WAM cannot be used as automatic positioning for the aircraft (VFR), but it would require positioning being sent to the aircraft somehow. WAM is also very accurate in altitude (+-20 feet), but I think that requires GPS to synchronize the ground stations. Without GPS it works with less accuracy AFAIK, especially in altitude.
Peter wrote:
Does anyone actually know what the plan is? I mean a document? Can anyone post a link, or the document itself?
I haven’t found an actual plan, but I have found the Eurocontrol handbook for developing contingency plans.
In short, for enroute and SID/STAR navigation it assumes that at least 90% of the fleet has DME/DME RNAV capability and is basically unaffected and remaining aircraft will be handled using VOR/DME and radar vectoring. For approaches, every airport must have some conventional approaches (ILS, VORDME…) for use in contingencies.
LeSving wrote:
Avinor just finished their WAM system this spring.
What is the WAM system?
Airborne_Again wrote:
What is the WAM system?
Wide-Area Multilateration.
arj1 wrote:
Wide-Area Multilateration.
So what is it? I could guess from the name, but it’s better with an explanation.
Different satellite systems offer some resiliency, but when a military power wants to jam, it will block all GPS signals, both from space and the ground.
I have to say this did cross my mind when they turned the NDB off at Le Touquet and the procedural approches became GPS to ILS.
I know the much maligned NDB gets some flack but it does work and must be very cheap to keep in service.
Airborne_Again wrote:
arj1 wrote: Wide-Area Multilateration.So what is it? I could guess from the name, but it’s better with an explanation.
Hi @Airborne_Again, sorry! :)
WAM is just a wide-area MLAT. MLAT – when the signal from a Mode-S is received by multiple ground-based receivers and the aircraft position is determined by timing, so you need at least three station at the same time. It is a fairly precise mechanism and together with MLAT becomes more and more popular for a civilian aircraft surveillance and tracking. MLAT apparently is more precise for ground ops than an airport radar.
Airborne_Again wrote:
What is the WAM system?
A bit old, but it’s like this. more or less.
The point in this context is that it works seamlessly with ADS-B, and will work as a backup in case of GPS jamming. It works for all transponder modes. It also replaces surveillance radars. Finland also newly installed such a system. It also means that flying VFR there is no possibility flying “below the radar” anymore Avinor has installed some 200 ground stations. I don’t know where, but according to press releases it will greatly enhance SAR missions, so I guess the coverage is more or less 100%.
arj1 wrote:
WAM is just a wide-area MLAT. MLAT – when the signal from a Mode-S is received by multiple ground-based receivers and the aircraft position is determined by timing, so you need at least three station at the same time. It is a fairly precise mechanism and together with MLAT becomes more and more popular for a civilian aircraft surveillance and tracking. MLAT apparently is more precise for ground ops than an airport radar.
Ok, so it is what Flightradar24 does with non-ADS-B out aircraft. (But much more precise, you’d hope.)
