Where Are We? - GPS Declassified: From Smart Bombs to Smartphones - page 168

eters near large quakes. By the time geophysicists calculated the actual
intensity more than twenty minutes later, authorities had lost valuable time
needed to alert people ahead of the waves. 162 nasa announced in April 2012
its collaboration with several universities and scientific organizations to test a
new warning system, the Real-Time Earthquake Analysis for Disaster (readi)
Mitigation Network. 163 It uses satellites to monitor about five hundred gps
ground sensors across California, Oregon, and Washington. 164 Scientists
involved in the project say the system could have established the magnitude
of the 2011 Japan earthquake within two to three minutes. 165
Along with precise positioning and navigation, the atomic clock accuracy
of gps time has become an unseen but ubiquitous background utility. More
than five hundred thousand timing gps receivers support industry around the
world. 166 They help millions of individuals and businesses to simultaneously
download and upload data across private networks and the Internet. Packets
of digitized information speed through electronic networks like vehicles on
crowded freeways, and precise time synchronization is a prerequisite to main-
tain smooth flow. Consider the importance of precise time stamping on large
electronic financial transactions when market prices are fluctuating rapidly. A
clock error of ten parts per million will grow to almost a full second in one
day. 167 Network technicians install time synchronizing equipment like Spec-
tracom's SecureSync system or Symmetricom's SyncServer sgc- 1500 Smart
Grid Clock, which keeps an electric utility's substation clocks synced to gps
time within one microsecond. 168 Precise time synchronization helps power
companies manage transmission networks, isolate faults, and balance loads.
It is a key element in making our electric grids “smarter” and more secure as
utilities begin to integrate dispersed renewable power sources, such as wind
turbines and solar cells, with traditional sources, such as centralized coal, gas,
and nuclear plants. In the telecommunications industry, most of the world's
half-million cellular base stations utilize gps timing equipment to switch calls
(usually seamlessly) from one tower to the next as mobile phone users drive
along roadways. 169
gps technology is seeping into other commercial and professional activities
as users find ways to improve accuracy, increase productivity, lower costs, save
time, or enhance safety. While commercial users account for a quarter of gps
equipment sales—less than half the consumer market—the $8.3 billion they
spend and the uses they make of gps yield a large economic impact. Estimates
of the aggregate economic benefits to all commercial gps users in the U.S.