Global Positioning System Reference
In-Depth Information
Locata functions like a localized ground-based gps without atomic clocks. A
Locata network does not maintain absolute time based on an external stan-
dard. Rather, individual base stations, known as LocataLites, synchronize time
with each other to within one or two nanoseconds. 84 An analogy would be a
cappella singers matching pitch to each other rather than, say, a piano. Tests
in October 2011 of an enhanced version of Locata's commercial of-the-shelf
system confirmed that it met Air Force accuracy requirements. A plane flying
at about 225 mph at an altitude of twenty-ive thousand feet over an area roughly
thirty by forty-ive miles dotted with ten LocataLite antennas demonstrated
horizontal accuracy of six centimeters (just over two inches) and vertical accu-
racy of fifteen centimeters (about six inches). 85 Locata's radio signals are more
powerful than gps, and they broadcast at the same frequency as Wi-Fi, mak-
ing it easy to adapt many current devices to use them. 86 The Air Force signed
a multiyear contract with Locata in September 2012 to install the system across
a 2,500-square-mile area of the White Sands Missile Range, and a veteran Air
Force gps manager has joined the company. 87
For the commercial sector and for consumers there are significant oppor-
tunities and challenges ahead in the area where most people first discovered
gps—surface transportation. Toll roads for years have used electronic tran-
sponders or bar codes to charge vehicles without stopping at tollbooths. gps
facilitates charging drivers by the mile, replacing gas-tax revenues lost to ris-
ing fuel efficiency. Switzerland implemented the first nationwide gps- based
toll system for trucks in 2003. 88 Germany followed two years later with a sys-
tem covering 7,500 miles of the autobahn, and today a patchwork of satellite,
cellular, and transponder systems covers Europe, spurring the development
of hybrid electronic toll devices for vehicles. 89 Proponents of vehicle-miles-
traveled (vmt) taxes in the United States face strong headwinds. A Congres-
sional Budget Office study found some potential benefits in reducing emissions
and addressing traffic congestion, but vmt taxes would be costly to implement
and raise privacy issues. 90 Add to that the normal resistance to new taxes. When
a North Carolina legislative committee floated the idea in 2009, a poll by the
conservative Civitas Institute found 70 percent of voters against it. 91 Around
the same time Transportation Secretary Ray LaHood, an Illinois Republican,
called vmt an option “we should look at” in an Associated Press interview.
White House press secretary Robert Gibbs dismissed the idea that same day. 92
Three years later the gop campaign platform explicitly opposed “any funding
mechanism that would involve governmental monitoring of every car and truck
 
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