Comment on ABC News: How accurate is your GPS?
Recently, ABC put out a news snippet about the “child killing” inaccuracies of GPS vehicle navigation units. Glossing over the semantically misleading title, the report did a decent job of quickly summarizing the obvious—navigational software is prone to errors. It is not that the receivers are inaccurate, but rather the GIS programming behind the directional software is not foolproof. Having driven sub-par vehicles all my life, I am well cautioned to not blindly trust ‘foolproof’ gauges like gas meters, speedometers, turn signal indicators, etc. I do trust billowing white steam as a statistically likely indicator that my car is overheating. So, where is the fault with the navigational systems and what can you do to lighten your chances of becoming a GPS child killer?
The various driving programs packaged by TomTom, Magellan, Garmin, DeLorme, and others, rely on a base map of roads. Already, there is going to be a spread of accuracy based on the detail of the map and the age of the data. Roads change; in some areas, a map can be outdated within a year. I live on a street that dead-ends against a creek and then shows up on the other side with the same name. It is not uncommon for folks to knock on our door wondering where the rest of the street lies. Some software allows for upgrades but it is up to you to stay on top of things. And, it is unlikely that daily, weekly, or monthly closures will appear. Secondly, in the better mapping packages, the roads are ‘weighted’ for traffic speed and other flow parameters. That way, you can mathematically deduce which is the best route even if it is not the shortest. We all know how this works whenever we try to explain to a friend or spouse that our way is “better.” Herein lies the problem. How many software packages are going to be more accurate than your knowledge, experience, and intuition for your neighborhood? Then why do you trust it for other neighborhoods you have never been to?
I blame the problem for the accidents and lost drivers on losing our ability to read a map and growing up in an increasingly virtual world. At some point in the Late Atarian, we evolved into a race that trusts virtual landscapes more than what is outside our window. Or, we just would rather inhabit that space. Why else would so many minivans and airplanes have TV sets instead of looking out the blessed window?
At this point, you may be wondering why I am writing about this on a fieldwork blog. Do you think the software for backcountry work doesn’t suffer the same shortcomings? In future blogs, I would like to explore how to improve the software we use for monitoring and recording our field work.
Tags: GIS, GPS, Mapping, software
You can comment below, or link to this permanent URL from your own site.
February 11, 2008 at 6:52 pm
gps mapping
yes indeed…