Bottom Line: Don't Worry; Be Happy.

With the possibility of the nation's going to "Code Red," and the expectation of retaliation, and the expectation of all sorts of unexpected hostile events' happening in this land, as the Iraq hostilities gain momentum, we wondered what, if any, changes we might expect in our GPS system. Specifically, we were wondering about whether there are plans afoot to once again reinstate "selective availability," under which civilians operated until May of 2000. (That system, you may recall, degraded the GPS system to our sets, resulting in an error margin 10x greater than the system could produce.)

We called the FAA, and they told us that, if any contingencies might be on the table (and they weren't saying there were), they couldn't talk about them, until such time as the TSA, DoD, or some other authority wanted them to.

We called a leading GPS manufacturer, and were told there were no plans, as far as they knew; but they, too, were civilians, and that they were under the same restrictions we all were, regarding access to information.

So, we called the folks who run GPS. Yes, Virginia, there is a whole agency that does nothing but watch over GPS, and think of things to make it better. It's called the Interagency GPS Executive Board, and they are headquartered in the Capital.

We talked with Paula Trimble [no relation] at the IGEB, and she told us, "US policy has not changed. We do not degrade the global service from its advertised capability." We know that the system isn't currently degraded -- that's fairly obvious; what we're worried about is the possibility that we might be flying a precision GPS approach, and -- poof! -- we're only within 50~100 yards, instead of the two meters we're accustomed to.

Ms. Trimble acknowledged that the ability to reinstate SA is a capability: "Consistent with national policy, the US government also maintains the capability to prevent the hostile use of GPS and its augmentation, while maintaining a military advantage in a theater of operations, without unduly disrupting or degrading civilian uses outside the theater."

So -- that left us kinda where we started. Ms. Trimble wanted to give us the best information she was allowed to give, and found one other official statement: "GPS Selective Availability has not been used since its use was discontinued May 1, 2000; however, the ability to deny the enemy regional access to GPS signals in an engagement does exist, as a military option. It is an option that would require very high-level policy consideration. If requested by the Commander of US Forces in the region [in the region of the conflict --ed]. Because of our national policy, this is not a decision our government would take lightly."

Would there be any warning, if SA were to be turned on? None of our experts and contacts would go on the record for this one, but they all agreed that it would be pretty stupid, tactically, to announce a degradation in advance.

So, we learned that there are no plans afoot to deny full GPS capability, except perhaps in an actual war theater; and we found out that, in order to degrade GPS accuracy, it would take very high-level involvement (and we reconfirmed that at least some government decisions are apparently "taken lightly").

FMI: www.igeb.gov; www.navcen.uscg.gov (check "GPS Status")