I'm not privy to any inside information but I understand from what I read that the feature is not present on the latest satellites. According to an official US government statement at gps.gov
Quote:
The U.S. Government also maintains the capability to prevent hostile use of GPS and its augmentations while retaining a military advantage in a theater of operations without disrupting or degrading civilian uses outside the theater of operations

Localized jamming and spoofing by US, foreign and non-state actors is always possible, as has been recently reported in the online technical media.

There is a website which for us users might be useful: it's designed for pilots to check forecast gps disruptions prior to flight, but I imagine it might be of interest to ground-based gps users too.

http://www.raimprediction.net/

I expect that when the UK military plan gps jamming activities they coordinate with the CAA and relevant notams are issued to pilots well in advance. I would be surprised if was anything other than announced months ahead,


Edited by Jarvis (07/29/12 07:19 PM)