On Aug 14, 2009, at 1:58 PM, Andrew Leach wrote: > > On Aug 14, 11:17 am, Rossko <ros...@culzean.clara.co.uk> wrote: >> >> For the car application, the interest would be in the accuracy of >> road >> placement, it doesn't matter at all if the coast is wrong. > > It may be worth noting that coastlines *can* be extremely accurate > *if* that data exists. Have a look at > http://www.achurchnearyou.com/parishmap.php?pcode=10/386 > for example: the red line comes direct from Ordnance Survey data > (correctly licensed!) which means the map coastline must have done > too. > > I do agree though, that the coastline probably isn't of much interest > to car drivers, so it's more likely to be an approximation than > actually accurate.
In all fairness, though, the TeleAtlas data is sometimes just OFF to the point of being useless. For a great example of this, check out Sitka, AK on maps.google.com. Compare the optical data to the road data. From my own personal GPS readings, the optical data (DigitalGlobe, GeoEye, TerraMetrics) is spot on, whereas the road data (TeleAtlas) is off by about 400m (a quarter-mile!) At least in that area, when it comes to any sort of lat/lon analysis, even on the most minimal of levels, the TeleAtlas data is complete garbage. I imagine Sitka isn't unique in this "feature." -G --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to Google-Maps-API@googlegroups.com To unsubscribe from this group, send email to google-maps-api+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---