Slide 23 of 29
This shows a sequence of temporally related objects.
What is more important is what features can be interpreted from rasters. We need higher level objects to hold those interpretations so that they can be manipulated as objects in their own right… so we do need to consider object-based systems whatever form our input data.
Temporal tools can be faster, easier to understand and more extensible iff we have a clear and appropriate representation underlying them.
This is true in ordinary GIS too: but we get away with it by embedding those concepts in the application software (not in the stored representation) and re-interpreting on the fly. But we know that proper mixed raster/vector working is better - it is just even more worth while for temporal GIS.
Relationships are the key to implementing everything in this model. The relationship from raster to object is <evidence>, that between objects is <next>. One object attribute is the valid timestamp at the object granularity. Transaction time can be on the object, or at some coarser grain (e.g. segment).
