it's a while back...
 

...but if I remember correctly, the gps signal is put together out of a p code and a c/a code, where we, as civilian users can only utilise the c/a code. Military users (i.e. smart bombs etc.) lock onto the p-code giving them a higher level of accuracy. Selective Availability was used to further degrade the c/a code, but was switched off (as mentioned before..).

please correct me if I'm wrong!

Thank-you expat and CASA

hptaccv,

Not sure what part it was that the Iraqis were jamming - but they were using Russian jammers and the USA didn't like it and bombed them out of existence, according to reports last week.