Here is the function I need to implement. My application deals with mobile objects with variable position and range (think of radar range). As I can't test each minute if n mobiles detect each other (server would be overloaded), I need to precalculate "future" position and time when they'll detect each other from their planned route and only register the "future" event in a stack. Each time a user changes the planned route, I'll recalculate event related to all intersecting routes from other mobiles.
The best way to do that is to make a kind of 4D intersection request and update, and be able to detect when and where mobiles will "collide".
Is it possible with a classic geodatabase like PostgresQL+PostGis and another plugin, or do I need to look at specific n-dimensional database ?