Originally Posted by
Old Akro
There used to be regular notams about it. Common sites were near Hamilton in VIC & Woomera in SA. GPS is a relatively simple broadcast at relatively weak levels. My understanding is that it is very easy to jam and that all military's have the ability to conduct localised jamming.
Some GPS data that I'm reviewing for a court case at the moment has a 12 tonne Motorhome doing over 160 km/h for 100 seconds. This is from a professional GPS data logger, not a consumer device. I was driving it and it wasn't. Clearly we have 100 seconds of corrupt GPS signal. Most probably it was a disturbed signal from building reflection or tree cover. The area of this disturbance was on the Princes Highway near Pakenham VIC. It doesn't affect my evidence in this instance, but does serve to illustrate the fragility of GPS.
By the way, if you are asking why it is less superior than other options, you have completely missed the point.
The pint is that GPS has fallibilities and reliability like other electronic nanvigation AIDS. It requires a back up alternative like other electronic navigation aids.
I've had a GPS antennae fail twice on an aircraft. I've never had an ADF fail.