Publishing location based data in Easting and Northing, Longitude and latitude, or Addresses?

Question

I am working on publishing a listing of shelters and hostels, I would like to expose my data to anyone who would like to use it. One of the things I would like to do is allow the shelters and hostels to be plotted on a map.

There are three methods of posting locational based data:

Addresses

This is the traditional street and Avenue system that the postage system uses.

Easting and Northing

These are (usually) used for horizontal and vertical from the a specified datum position. For example, a mountain close to where I live is located at 50° 52′ 10″ N, 115° 39′ 3″ W.

Longitude and Latitude

This is a common grid system that uses two numbers (a coordinate) to pinpoint a location. For example, the same mountain can be fount at 50.869444, -115.650833.

My thoughts so far

The addresses system good for projects in a city but if the location is away from a road (like some hike-to hostels) it does not work so well. My data is already in Easing/Northing, however with everyone using GPS and cell phones now it sounds like longitude and latitude may be more popular?

Question

What type of location system should I chose if I want as many parties as possible to use my data in their work? It's hard to know how the data could be used, but I suspect consumers of my data to be interested in travel, real estate, poverty and government.

Answer 1

This is very problem-dependent, but if the most likely use of the data is for positions to be plotted on a map (rather than, for example, sending mail to those places) then the data should be given as positions, rather than street addresses. This way they are unambiguous, wheras addresses may change over time, and the locations that correspond to them may depend on what lookup tool is used to convert addresses to locations.

If you're giving location data, then the most important thing is not the exact format that you give it in, but that it is clear what the format is. Coordinates should be accompanied by metadata explaining what the coordinate system is. For example,

• If using lat/lon, you should ideally note what geoid is referred to (usually WGS84 these days, since that's what GPS uses, but best to specify if you know).

• If it's something more complicated (e.g. UTM coordinates) then that needs to be clear and the appropriate metadata given.

• If vertical elevations are given, it's important to know what datum is used (i.e. where is zero elevation).

With regard to your specific dataset (and without knowing the details of the likely uses) I would recommend giving position data rather than address data, and (less importantly) expressing that in degrees rather than degrees / minutes / seconds, because in many cases it will be easier for software to parse.