Ported from python library here: https://github.com/ashwin711/proximityhash.

Geohash is a geocoding system invented by Gustavo Niemeyer and placed into the public domain. It is a hierarchical spatial data structure which subdivides space into buckets of grid shape, which is one of the many applications of what is known as a Z-order curve, and generally space-filling curves.

Image from original repo to demonstrate output:

require 'proximityhash'

proximity_hash = ProximityHash.new(latitude, longitude, radius, precision_level)
proximity_hash.calculate

• latitude in decimal degrees
• longitude in decimal degrees
• radius in metres
• precision_level between 1 and 12

A hash of geohash (key) and distance (value) (in metres) ordered by closest to further away.

Apache 2.0