SIS-1 out of the way, I'll begin work on refactoring what we've got for SIS so far.
After reading , I think we should begin with the definition of a spatio-temporal reference identified there:
Any measurement we take in Earth and environmental sciences, although this is often ignored, has a spatio-temporal reference. A spatio-temporal reference is determined by (at least) four parameters:
1. geographic location (longitude and latitude or projected X,Y coordinates);
2. height above the ground surface (elevation);
3. time of measurement (year, month, day, hour, minute etc.);
4. spatio-temporal support (size of the blocks of material associated with measurements; time interval of measurement);
I'm going to use this issue to track that focus of the initial refactoring.