Geohash-36

Geohash-36 is an open source compression algorithm for encoding world coordinate data into short alphanumeric strings. Unlike the widely used Geohash system, which encodes coordinates in a base-32 alphabet, Geohash-36 uses a 36 character, case-sensitive alphabet that deliberately excludes vowels and visually ambiguous characters, a choice meant to make the resulting codes easier to read, speak and use safely inside URLs. The two systems are independent of one another despite the similar name: Geohash-36 divides the world into a six by six grid at each level of precision, with each character in a code selecting one cell of that grid moving from the northwest corner toward the southeast, so that adding characters to a code narrows the encoded area and increases precision. A code can carry an optional altitude component, prefixed with a capital A for a position above sea level or a lowercase a for a position below it, and an appended checksum using lowercase letters lets a reader validate that a code has not been corrupted or mistyped.