But there's more to it than that.
The story begins with an e-mail from a reader who wrote, "Google mapping technology is falling apart."
If true, that claim would make an interesting story. Given that a similar report appeared this morning in The Register, stating that Google had erased Malta, it seemed plausible.At it turns out, Google Maps and Google Earth, which rely on the same data, do indeed exhibit occasional glitches, as do Yahoo Maps and Windows Live Local for that matter. Road overlay graphics don't always align with the roads shown in satellite photos. As you can see from this picture, Southland Drive appears to pass through a shopping center.
Google spokesperson Megan Quinn suggested I take up the issue with the company's satellite data imagery provider, Digital Globe. "All of the satellite imagery available in Google Earth and Google Maps is provided by third party data providers," she wrote in an e-mail. "In this case, the imagery is provided by Digital Globe and we recommend contacting them for further details about imagery alignment. We are constantly working with our data providers to bring users the most accurate and detailed imagery of the world around them."
Fair enough. So I talked to a spokesperson at Digital Globe, and he said that Digital Globe didn't provide the GPS overlay information, just satellite photos. Other companies provide the GPS data layers. I quickly realized I could spend years following the circle of finger-pointing.
Let it suffice to say that somewhere in the sausage making, mistakes have been (and are being) made. Objects in Google's digital mirror of our Earth are not exactly as they really appear. The same goes for Microsoft and Yahoo. Caveat emptor and all that. Mostly, online mapping services work pretty well.
"Is it because we live in Canada that our maps do not require the detail of the USA?" asked the vexed tipster who raised the issue in the first place.
That I can't say. But next time I find myself driving in Calgary, I'll make sure to keep my eyes on the road rather than on my rental car's GPS navigation system.