SEP 39: Metadata: Enhanced location

Currently the location metadata element is a simple string referencing the city I was in (or based in) when a document was written.

I was struck today by the thought that this information could be expanded/enhanced to include more depth/granularity. The two proposed enhancing elements would be coordinates and place. The first is fairly self explanatory, latitude and longitude of the location. The second, place, is a richer and more personal location property. It could be ā€œIn the cabinā€, ā€œAt Paulā€™s house for dinnerā€, ā€œIn a Yaza cafe in Montgomery squareā€, it is the context for ā€˜whereā€™ I am. In fact context might be a better name for this element.

Thus, I propose this richer location metadata as follows:

location:
    locale: Bristol, United Kingdom
    context: Coffee and chat at Boston Tea Party with Dale
    latitude: 51.480311
    longitude: -2.5885995

Privacy considerations

The intent of this richer metadata is primarily personal, but portions of it will be distributed widely and thus must be made ā€˜safeā€™ in terms of sensitive location information. Generally speaking it takes accuracy of four decimal places (eg. 51.4803) to specifically identify a building, three decimal places (eg. 51.480) is sufficient to identify a street, two places (51.48) gets you a post/zip code, and one reduces you to the resolution of ā€˜nearest cityā€™.

Coordinates in document frontmatter should be specified at the highest accuracy available to facilitate rich use and re-use of this data into the future, but in all cases of a document being shared publicly (such as on this website) those coordinates should be truncated to two decimal placed

Figure 1: A global heatmap
Example of a heatmap from Wikimedia Commons opencellid.org, CC BY-SA 3.0, via Wikimedia Commons

Long-term I envision this data facilitating a geographic heat map of all my writing, visualizing both the centres/hubs from which I write most but also the paths I have taken through the world as represented by the documents/fragments that emerge from those journeys (see Fig 1 for a borrowed example).

My limited understanding of Spatial reference systems leads me to believe that using a Geographic coordinate system (ie. Lat/Long) is best fit here ā€” as opposed to a Projected (planar) coordinate system (ie. Easting/Westing). If any GIS experts should happen across this proposal and feel differently then please do reach out.