On 7/10/22, Gary Lucas wrote:
The other motivation for the block scheme is that the API provides random-access to data. Typically, if one is looking at data for Finland, one usually doesn't care much about the data from Australia.Thus the file is divided into regional blocks. So the choice of block size also reflects the way in which I anticipate applications would use the data.
I hope you are aware that such a system has been in use for about seventy years, exactly for this purpose, namely the Universal Traverse Mercator system which uses 70 rectangular zones (some of them slightly overlapping). See https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system . Most serious public Earth spatial data systems are based on UTM coordinates. If your system does not interoperate with UTMs then nobody will talk to you. Various package delivery corporations have proprietary systems that are quite similar. United Parcel Service (UPS) in North America, DHL (a division of Deutsche Post) for much of the world, and others. Amazon had a coordinate system that specified points for delivery in the first 48 US states using two 16-bit integers. Google Maps identifies locations on Earth using about 7 characters which encode a recursive nested quadrant system. I'm pleased that you consider altitude. There are places in Grand Canyon National Park (Arizona, US) which have the same (x, y) coordinates but are several hundred feet apart. It takes a few hours to walk from one instance to another "same" (x, y) point. And if you are delivering ice cream cones to someone in a sky-scraper tall building, then it can take minutes to travel from the street entrance to an upper floor. --
