New GPS Satellite Launched

zonker writes "A U.S. Air Force Delta 2 rocket launched a new GPS satellite today to add to the collection of 27 up there. This new GPS satellite is one of seven now in orbit as a replacement for an earlier generation of GPS. May be of interest to the GPS folks out there."

Comments

Re:GPS errors

[Throw Away Account]

"sort of shifty"?

It wasn't a secret the military tried to keep; they told you straight out that the civilian channel had deliberate inaccuracies in it to degrade its military value for potential hostile powers.

Hardened military targets (bunkers) and mobile armored targets (tanks) are very hard to destroy with accuracies of 100 meters; they are very easy to destroy with accuracies in the single meter range. And hundred-meter accuracies were good enough for most civilian navigation, whether by hikers, boaters, or pilots.

And Clinton didn't lift the restrictions out of the goodness of his heart, either. It's just that techniques that compared the GPS-reported and known actual coordinates of landmarks allowed for correction of civilian data to military-level accuracy*. So separate levels of access were no longer benefiting national security.

*Ironically, the Coast Guard pioneered these techinques, since they weren't given access to the military data.