Slide 15 of 29
Now we are getting somewhere. This is Yuan’s example of Warboy’s model, which he tested using Smallworld GIS.
Every object has both geometric and temporal attributes. Successive states of an object are different objects with different OIDs and need an explicit relationship.
No homogeneity of timestamping is required. Objects can change asynchronously; but all the attributes of an object change (or are copied).
This is how Laser-Scan uses its OO GIS to provide cadastral applications.
Neither Smallworld nor Laser-Scan provide any index for the times: you have to navigate the relationships.
Example and diagram from May Yuan’s paper on NCGIA website.
