Open Location Code | Hacker News Reader

Open Location Code

openlocationcode.com

29 pointscoolvoltage5 comments

Another option is EZCOD: all the features of Open Location Codes, plus error detection and correction using Reed-Solomon FEC (forward error correction), in C++, Javascript or Python:

https://github.com/pjkundert/ezpwd-reed-solomon

A reference implementation is online at http://ezcod.com

More details at http://hardconsulting.com/products/13-reed-solomon

TL;DR

Friends don't let friends use geolocation codes without error detection! You'll end up in the wrong hemisphere...

A code like "R3U 1JU QUY.0" gets you within +/- 3 meters of the coordinates 53.655832,-113.625433 -- with the ability to recover from 1 lost symbol, or a certainty of P(.969) that the presented code is correct.

Optionally, 15 symbols gets you within +/- 20 millimeters of any location on the planet with P(.99997) certainty of correctness, or recovery from up to 3 missing symbols, or 1 erroneous symbol while retaining P(.969) certainty of correctness!

Yeah they list a lot of requirements on this page: https://github.com/google/open-location-code/blob/master/doc...

Oddly I don't see redundancy (error detection or better yet, error correction) in there but it seems to be an important part of human language. They do make an effort to reduce symbols that could easily be confused at least.

Suprised they did not include error correction in the requirements list, at least in the canonical/long form.

There's also what3words [0], which uses 3 English words. They support a few other locales/languages I believe.

Their idea seems better from a human-readable perspective, and I prefer the solution to other concoctions like what Waytag [1] once did. Although Waytag founders focused on 'our technology is patented, soon Google and all the other giants will be licensing from us' part [2] instead of improving their user experience and creating a decent API. Their patent later got invalidated with GeoCities as prior art. I tried to find the detail on Stack Exchange, I'll add reference when I find it.

[0] http://what3words.com [1] http://waytag.com [2] http://support.waytag.com/our-vision/

Having the city on there is maybe more readable in many ways. The other thing that sets this apart from what3words is that what3words won't give out their word list as far as I can tell. This could be because they have taken $5 million in funding.

Reply on news.ycombinator.com