OpenStreetMap
A couple of weeks ago I was looking at Google Maps in the southeast area of Morgan Hill, California for assistance in updating OpenStreetMap. I found numerous errors, some of them rather severe, and reported them to Google for correction. Even though they acknowledged my submissions as being correct, so far nothing has changed when I look at the same area. Moreover, it seems that Google Maps was more accurate as recently as a year or two ago. They seem to have imported some new databases that are riddled with errors.
That said, OpenStreetMap has the potential to become much more accurate and useful than Google Maps. However, the aerial photography that is supplied by Yahoo! is terribly out of date. For instance, the new Morgan Hill Library was built in 2006-2007 and dedicated in July 2007. The aerial photo for the Morgan Hill Civic Center still shows a graded lot with some construction equipment around the edges, so it was probably shot in the late summer of 2006. That's nearly FOUR YEARS ago! What can we do to get new aerial or satellite imagery?
Discussion
Comment from andrewpmk on 2 May 2010 at 01:42
This seems to be a perennial problem with Google Maps and other proprietary data. For instance, Google recently (a few days ago) rolled out new data for Canada, which is mostly derived from GeoBase government data (which OpenStreetMap is also using). It is full of errors and omissions, for instance the lack of the recently opened northern extension of Highway 410 in Brampton which is correct on OSM. My only advice is to keep mapping and NEVER use Google as a data source.
Comment from user8192 on 2 May 2010 at 02:06
I happen to live in Morgan Hill, so I have the choice of checking an online map or taking the time to get into the car or hop onto a bicycle, going to the area in question and checking it out in person. Sometimes even working from memory seems to produce better results than using Google Maps, Mapquest or Mapblast!
Comment from Komяpa on 2 May 2010 at 07:26
Try out Google Maps mutator that makes all the google maps better ;)
http://www.openstreetmap.org/user/Komяpa/diary/8328
Comment from chillly on 2 May 2010 at 12:52
Rather than trace from Yahoo, why not go out an gather the real, up-to-date data from the ground? It's fun and it's makes the best maps.
Comment from pavithrans on 2 May 2010 at 18:01
Yahoo imagery is of no use for me as for the given zoomlevel I cant even identify my small town in India . Google was the same 3 years back but 1 year back a satellite has visited and gave great imagery which lead to huge contributions to g maps . I am trying to get most of the data via GPS .
Comment from user8192 on 4 May 2010 at 00:41
@chilly, I don't have a GPS unit at present, and I value my health and safety too much to go out into the street with a compass and tape measure.