CODEWITHSUNDEEP
google-mapsgeolocationgeocode
user11977
user11977

Reputation: 1793

Geocoding with Google Maps API - accuracy and limitations

It is easy to use the Google Maps API to find a specific street address and return the latitude and longitude. For example, link.

However, it appears that typing in the name of a specific location, for example a park, causes problems. Often these don't have a specific street number (at least, not easily findable). Despite the fact that Cadigal Reserve is located at the same address as in the link above, if I enter that as part of the query string and remove the street number, the results become rather useless: link

Typing this directly into maps.google.com easily finds the park itself (and of course, you could then find the latitude/longitude by looking in the URL).

Is there not any way of using the Google Maps API to geocode a park location like this?

Upvotes: 4

Views: 2409

Answers (1)

Fraser
Fraser

Reputation: 17039

It is important to understand that geocoding is not an exact science. The recommended practice if you have addresses that you know should geocode to a specific location is to build a cache and use local (client-side) geocoding.

In version 2 of the api you would build your own client-side cache that contains pre-computed geocoder responses by extending the GeocodeCache. Once a cache is defined, you would call the setCache() method and away you go. This is pretty much explained here:

http://code.google.com/apis/maps/documentation/javascript/v2/services.html#Geocoding_Caching

However, AFAIK GeocodeCache was removed in V3 of the api...

So, I would suggest implementing your own client -side caching-strategy of known addresses and their corresponding coordinates. When your application receives a geocode request for a known address the response would come from your cache (rather than Google's geocoding servers).

Failing all that you can always use a payed geocoding service that, in theory, will have a much more accurate dataset (as well as a higher limit on requests, etc).

Finally, you should also take a look through the Geocoding Strategies document as it gives a good handle on some of the issues here.

Upvotes: 1

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