Notes from Data Model break out session
- Carsten Roensdorf

 Not much of a difference between Inspire, LandInfra and CityGML data models: rather: lot of commonalities between the three from a utility perspective

               Could extend Inspire utilities to 3D
               Could/will extend LandInfra to utilities
               CityGML is more generic

       Voxels is a very interesting concepts
       Gavin: I came to the meeting with questions, now I have more questions
               Good to see that there's a lot of effort on existing models

               Other models
                       GeoSciML
                       IFC

               Focus on maybe 3, are all attributes we need there

               Should we include the surroundings of the infrastructure

               Semantics: we confuse the word model
                       Simulation of behaviour
                       Vs the 'lego'/ Real word model
                       Data model  - structure you put the data into / how you describe data
                               Metadata or instance data

               Virtual Twin: every thing in the real world has a corresponding element in virtual reality .. For purpose, simulation, ...

               Network to network relationships, i.e. telecoms: interconnect between suppliers, but also water pumps and electricity, sub-networks, hierarchical networks
               Multiple representation
               Asset lifecycle
               Logical, geoscematical, schematical
               Vector vs voxels
               Separation between objects (describe a pipe as object with one link or collection of links)
                       CityGML utility network supports different LoDs, i.e. with or without indiv components
                       Could also have lines or extrusions, but not implemented
               Geometry LoDs and network granularity (- how you generalise the graph structure + repair patches)
                       Currently not fully defined LoD levels

               2-dimension of LoD - navigation data has this, for complex street data.

               Absolute height and invert depth or relative to another underground asset

               Referencing: linear referencing, cross-references (for multiple representation)

               Functional and lifecycle as different modelling paradigms
                       Asset management and lifecycle of individual feature, inventory, like maintenance, repair

               Should we say something about nodes and links : well understood

               From a city manager perspective: ownership needs to be understood and when it was surveyed
                       -> metadata
                       Legal boundaries, spaces

               At what point in time the pipe is included in the database, planned, approved, as built

Issues
       Paradigm -> Everytime time you open the street you do something with the data and update the model
               Take a picture, do something: i.e. store the picture
               Data model to enable this:

       If we exclude GeoSciML, we currently don't represent
               Probability - geoscience mindsets : probability of what is there which has 2 different levels. -> Relate to stochastics in our currently fully deterministic models

               We're missing something about digging holes
               Legal spaces underground are missing

               We have extended the above ground data modelling of vectors representing crisp hard objects underground. It's not always useful

               Unstructured data: Layers: store not just the (final) vector model

               Networks are covered
               Hollow spaces are covered

               Voxels/functions in space
                       ->areas where we need to be careful
               Represent a cable as a probability function in addition to a line(string) geometry - could be dynamically generated (as per Ben's suggestion)

Actions
               Do table comparing the data models
               Could explore 2 data models
               Is it feasible to go from one model to the other (conceptual and data instances)

               Learn from geologists

               Represent ownership in a variety of different ways

               Network LoDs - define this. Build a topology from linear features

See if we can make use of ASCE 4 levels of reliability