- Published on Wednesday, 13 November 2013 00:11
- Written by Marlene Cowan - Special to the Town Crier
That tiny global positioning system chip in cellphones has had a big impact on society, according to GPS expert Frank van Diggelen, Ph.D., who appeared at the Rotary Club of Los Altos meeting Oct. 24.
Van Diggelen is senior technical director at Global Navigations Satellite Systems, chief navigation officer at Broadcom Corp. and consulting professor at Stanford University, where he teaches a graduate course on GPS. He holds 69 U.S. patents and won the Institute of Navigation’s Thurlow Award for outstanding contribution to the science of navigation in 2010.
We are living through a huge technology transition that allows access to navigation, formerly limited to the elite, to the general population, van Diggelen said, a shift equivalent to the development of the printing press in the 1500s, which brought literacy to the masses, or the development of computers in the 1980s, which made personal computing available to the general public. Smartphones produced since the first 3G iPhone have GPS capability linked to the 32 satellites now in orbit, he added.
Satellite navigation began when Sputnik was launched in 1957, van Diggelen said. It broadcast radio signals that reached Earth in 70 milliseconds. The time delay and Doppler effect could be measured to establish locations on the planet. The U.S. Navy built the first GPS for Polaris submarines. Satellites’ atomic clocks keep time accurately to a billionth of a second. There is just one line of code in smartphones that establishes their GPS location, van Diggelen said.
In geoscience today, fixed reference stations measure crust motion on Earth accurately to millimeters. A receiver near Stanford University indicates that the Los Altos area moves northwest 3 inches per year, van Diggelen noted.
He predicts a “big future” that includes GPS forensics to prove where a person’s cellphone is located at any time, and autonomous vehicles that communicate other vehicles’ positions for safe, automatic driving. With GPS, even “economically efficient” traffic lights may become available.
“How much are you prepared to pay for green lights?“ van Diggelen asked the Rotarians.
Marlene Cowan is a member of the Rotary Club of Los Altos.