Geography Reference
In-Depth Information
Chapter 10
OVEREDGE
n.
: the portion of the map that lies outside the neatline border
Look for the secrets half buried like trinkets in a field, Hope that the hidden things
someday will be revealed.
—JOHN DARNIELLE
A
t midnight on May 1, 2001, some unnamed hero at U.S. Air Force Space Command,
locatedonthehighplainsjusteastofColoradoSprings,pressedabutton,anditaffectedmil-
lions of people all over the world. Most of the things the government can do at the push of a
button
don't
immediately improve our quality of life, but this action, ordered by the presid-
enthimself,madelifetentimesbetterformapnerdseverywhere.Justlikemagic,theGlobal
Positioning System—an array of twenty-four satellites in medium Earth orbit—could now
tellyouwhereyouwerestanding,anywhereonthesurfaceoftheplanet,towithinjustafew
meters of accuracy.
Acynicmightpointoutthattheonlyreasonthemilitaryhadthepowertomakethesystem
so much better at the touch of a button was that it had been lying to us all along. The first
GPSsatellite hadbeen launched way back in1978,butonlygovernment users hadaccess to
the real data. Civilian owners of GPS receivers got a scrambled signal that introduced ran-
dom error, so that most of the time their location information would be off by hundreds of
feet. Giving citizens the wrong answers to important questions is nothing new for the U.S.
government, of course; the IRS has been doing it for years. But in this case, the error was
intentional, baked into the signal for reasons of national security.
Butbythelate1990s,thisscrambling,euphemisticallycalled“selectiveavailability,”was
becoming obsolete. The military had figured out how to localize its GPS jamming in places
where secrecy was an issue, and a new ground-based technology called Differential GPS
wasallowingcivilianstoimproveonsatellitedataanyway.SoPresidentBillClintonordered
“selective availability” to be turned off altogether, and in the spring of 2000, White House
science advisor
Neal Lane announced
the big moment. “All the people who've bought a
GPS receiver for a boat or a car, or whether they use one in business or for recreation, will
find that they are ten times more accurate as of midnight tonight,” he told reporters.
In Portland, Oregon, that night, a computer consultant named Dave Ulmer stayed up to
watch the change on his GPS receiver, a clunky Magellan 2000 that he'd bought back in the
mid-1990s, when the year “2000” appended to a product name still sounded sleek and fu-
turistic. “It was really quite a momentous thing to see happening,” he says. “I still have the
track logs that I recorded during that event.” One minute he had a three-hundred-foot radius
