Location, latitude/longitude, and precision

["Wunder, John A." <jwunder@mitre.org>]

Hey everyone,

 

We’ve been having a conversation about the best way to represent the precision of a given latitude and longitude pair. What I mean by that is, if I give you 45.234234 latitude by 45.2342 longitude (literally just typed random numbers there) is that describing an exact point, just pointing to a city center, or even just pointing to a country?

 

We have a couple options here:

 

1. Just define in normative text that, for STIX, latitude and longitude is approximate. This would mean that you couldn’t really rely on it to be accurate to an address, even in cases where it was.
2. Have an optional property to represent the precision. If the property is present, it describes the precision in terms of meters. If absent, we have two options:
   1. Precision is unspecified, and consumers can take that however they want
   2. Default precision to perhaps 10km (roughly a zip code), so consumers can pretend the value was that
3. Have a required precision property

 

We also talked about significant digits but due to the ways JSON parsers read data it would mean using a string and likely that data would also be lost in those cases too (and even if there it’s harder to get to). It didn’t seem like a great option compared to any of the above, but maybe we’re missing something.

 

So, what do people think? Any other arguments for one or the other?

 

I don’t have any strong opinions really other than that #3 is probably not workable (producers would just make up a value in a lot of cases).

 

John