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geohashing

Geohash: How much hash length is enough

For an application that needs to store Geographical location of a person in the form of Geohash, how much hash length (in characters) would be enough?

The code located here (referred in Wikipedia article on Geohash) says:

    #define MAX_HASH_LENGTH 22

But they haven't mentioned any reason for that.

Solution

  • Some justification can be found on other topics:

    geohash-and-max-distance

    geohash-string-length-and-accuracy

    To localize a person, you would probably need a one-meter accuracy. 10 characters should be enough.