As we all know, GPS is practically perfect in every way — as long as it’s outside and unobstructed. Even cell phones can now produce meter-level accuracy under open sky. There are still many deficiencies in state-of-the-art location, particularly in deep urban canyons and inside large buildings. Which technologies will lead personal navigation into the future?
At the start of a new decade, let’s examine the state of the GNSS consumer market and technology. In the December 2009 issue of GPS World, I described the developments that put GPS in cell phones over the last decade. That technology revolution has brought GPS a very long way. Having come this far, we can ask that most famous of all navigation questions: Are we there yet?
Seven technologies put GPS in mobile phones around the world. Here is the how and why of location’s entry into modern consumer mobile communications.
This update to a seminal article first published here in 1998 explains how statistical methods can create many different position accuracy measures. As the driving forces of positioning and navigation change from survey and precision guidance to location-based services, E911, and so on, some accuracy measures have fallen out of common usage, while others have blossomed. The analysis changes further when the constellation expands to ombinations of GPS, SBAS, Galileo, and GLONASS. Software scripts, provided online, help bridge the gap between theory and reality.
“There are three kinds of lies: lies, damn lies, and statistics. So reportedly said Benjamin Disraeli, prime minister of Great Britain from 1874 to 1880.
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