Recently there was an intentional GPS outage in the California / west coast of the US. http://www.thedrive.com/the-war-zone/17 ... r-exercise
In the case of a global outage - say some kind of war broke out - and GPS was shut off unexectedly, what would be the impact on airtraffic?
Thanks FFF
Moderators: richierich, ua900, PanAm_DC10, hOMSaR
-
- GalaxyFlyer
- Posts: 12403
- Joined:
Re: GPS question
Well, nuclear war would put an end to Civil traffic, see 9/11-9/14/2001. Once traffic started up, ground-based navaids and inertial nav would be used, assuming no EMP damage.
GF
GF
-
- Florianopolis
- Posts: 382
- Joined:
Re: GPS question
Air traffic tools that require GPS would be unavailable (like T routes and GPS approaches).
Don't forget that many airplanes don't have GPS, even modern airliners. They're still RNAV capable because the FMS is using things like VORs and DME and INS to determine exactly where it is. In airplanes with GPS, it's just another input for the navigation system, and the system uses the same performance monitoring to verify the integrity of the GPS data.
Question for the forum: Are any modern airliners using doppler radar for navigation?
Don't forget that many airplanes don't have GPS, even modern airliners. They're still RNAV capable because the FMS is using things like VORs and DME and INS to determine exactly where it is. In airplanes with GPS, it's just another input for the navigation system, and the system uses the same performance monitoring to verify the integrity of the GPS data.
Question for the forum: Are any modern airliners using doppler radar for navigation?
-
- RetiredWeasel
- Posts: 942
- Joined:
Re: GPS question
flyflewflown wrote:Recently there was an intentional GPS outage in the California / west coast of the US. http://www.thedrive.com/the-war-zone/17 ... r-exercise
In the case of a global outage - say some kind of war broke out - and GPS was shut off unexectedly, what would be the impact on airtraffic?
Thanks FFF
NOTAMs were issued that said there could be a possibility of GPS interference within the area's mentioned around Nellis during the exercise. There were NO widespread reports of GPS outage from airliners. The USAF was covering their butts while using very localized GPS jammers. Sometimes the effects exceed the expected limitations.
-
- GalaxyFlyer
- Posts: 12403
- Joined:
Re: GPS question
Doppler has been gone as a navigation tool for 40 years. The 707/DC-8 were the last Doppler planes.
GF
GF
Re: GPS question
flyflewflown wrote:Recently there was an intentional GPS outage in the California / west coast of the US. http://www.thedrive.com/the-war-zone/17 ... r-exercise
In the case of a global outage - say some kind of war broke out - and GPS was shut off unexectedly, what would be the impact on airtraffic?
Thanks FFF
There ar multiple global GNSS systems, GPS is just one system run by the US. Other systems either up and running or being deployed include BeiDou, Galileo, GLONASS,NAVIC,QZSS. More are planned.
What we put on our flight plans is GNSS capability, it does not necessarily mean GPS capability.
They do not need to turn GPS off to make it unavailable in different areas, the simplist way to confuse receivers is to send out adjusted navigation messages which includes ephemeris data used to calculate the position of each satellite in orbit, and the almanac information which send out the time and status of the entire satellite constellation. By adjusting these the GPS satellites can still transmit there normal carrier signal, however when the receiver tries to solve the location of the receiver from each satellite as where they believe the satellite is the distance from that satellite does not make sense so true salettie is rejected. When they do this over multiple satellites the receiver is unable to make a position solution.
Thales for some time has had certified multiple network GNSS receivers like the TopStar C (EASA and FAA certified) which is on the ATR which gets around these issues.
Re: GPS question
GalaxyFlyer wrote:Doppler has been gone as a navigation tool for 40 years. The 707/DC-8 were the last Doppler planes.
GF
No, the Marconi AD660 was on the 727 and 737.
Re: GPS question
GalaxyFlyer wrote:Interesting but whose?
GF
British Airways and Lufthansa were the launch customers
https://www.flightglobal.com/FlightPDFA ... 203522.PDF
-
- GalaxyFlyer
- Posts: 12403
- Joined:
Re: GPS question
Timing is everything, laser INUs were not far in the future when this set was introduced. Gulfstreams and early Challengers had Delco Carousels installed within 4 years and, if course the B767 was introduced two years later with the first lasers.
Interesting use in determining ground speed for anti-skid.
GF
Interesting use in determining ground speed for anti-skid.
GF
Re: GPS question
GalaxyFlyer wrote:Doppler has been gone as a navigation tool for 40 years. The 707/DC-8 were the last Doppler planes.
GF
Right you are. Bendix dual Doppler with an EDO 600T Loran A, got me all over the world in the 707-320/720B. Then Omeg and next INS
Who is online
Users browsing this forum: dstblj52, steamgauge and 25 guests