W3C home > Mailing lists > Public > public-sdw-wg@w3.org > May 2017

SDW BP Glossary Issue 191: Geohash

From: Little, Chris <chris.little@metoffice.gov.uk>
Date: Thu, 4 May 2017 10:46:16 +0000
To: Linda van den Brink <l.vandenbrink@geonovum.nl>, "Tandy, Jeremy" <jeremy.tandy@metoffice.gov.uk>
CC: "public-sdw-wg@w3.org" <public-sdw-wg@w3.org>
Message-ID: <3DAD8A5A545D7644A066C4F2E82072883E2CA3DC@EXXCMPD1DAG4.cmpd1.metoffice.gov.uk>
1. "Geohash: A geocoding system with a hierarchical spatial data structure which subdivides space into buckets. Geohashes offer properties like arbitrary precision and the possibility of gradually removing characters from the end of the code to reduce its size (and gradually lose precision). As a consequence of the gradual precision degradation, nearby places will often (but not always) present similar prefixes. The longer a shared prefix is, the closer the two places are. Wikipedia"

2. Presumably the Wikipedia article is not considered definitive enough? Or is it a question of being slightly too proprietary? Nearly all geocoding system are, and even more, patent encumbered. So, unsurprisingly, there does not seem to be an ISO or any other definition other than the specific geohash.org web services.

3. I propose tweaking the definition to make it slightly easier to understand, highlighting the specific nature and staying with the Wikipedia reference:

"Geohash: A specific geocoding system with a hierarchical spatial data structure which subdivides space into nested regions. Geohashes and some other geocoding systems offer properties like arbitrary precision and the possibility of repeatedly truncating characters from the end of the code to reduce its size and precision. As a consequence of the gradual precision degradation, nearby places will often (but not always) present similar prefixes. The longer a shared prefix is, the closer the two places are. Coordinate and address systems generally do not have this property. [[https://en.wikipedia.org/wiki/Geohash|Wikipedia]]"

Chris Little
Co-Chair, OGC Meteorology & Oceanography Domain Working Group

IT Fellow - Operational Infrastructures
Met Office  FitzRoy Road  Exeter  Devon  EX1 3PB  United Kingdom
Tel: +44(0)1392 886278  Fax: +44(0)1392 885681  Mobile: +44(0)7753 880514
E-mail: chris.little@metoffice.gov.uk  http://www.metoffice.gov.uk


I am normally at work Tuesday, Wednesday and Thursday each week



Received on Thursday, 4 May 2017 10:46:51 UTC

This archive was generated by hypermail 2.3.1 : Thursday, 4 May 2017 10:46:51 UTC