Providing methods for the capture and analysis of dynamic phenomena through a PostgreSQL extension
- 1. Providing methods for Peter Broßeit the capture and analysis of dynamic phenomena through a PostgreSQL extension
- 2. Is the time still an issue in geoinformatics? 1
- 3. Is the time still an issue in geoinformatics? Which land use features are the predecessors of a particular nature reserve? Capabilities for spatio-temporal analyses in today‘s GIS are at best vestigial Data storage through existing data types –> No unified modelling in the time dimension 2
- 4. Concept • Modelling the valid time dimension with one user defined data type • Instants, periods of time and temporal complexes • Based on ISO19108 Actual Purpose: Unified modelling -> homogeneous queries Explicit modelling of periods of time and temporal complexes 3
- 5. Temporal Schema - ISO19108 Schema to describe the temporal characteristics of geographic information Feature attributes, feature operations & feature associations • Temporal objects • Various reference systems • Combination with features 4
- 6. The Temporal Objects TM_Primitive ISO19108 5
- 7. The Temporal Objects TM_Primitive ISO19108 MultiPrimitive 6
- 8. The Temporal Objects TemporalPosition ISO19108 7
- 9. The Temporal Objects TemporalPosition ISO19108 8
- 10. The Temporal Objects TemporalPosition ISO19108 Only one internal system 9
- 11. Textual Representation • Necessary for the information exchange -> The user’s view on the database level • Some terms are set by the Temporal Schema (ISO19108) The concerning standardisation does not go far enough -> Requires arbitrary specifications -> Only restrictedly suitable for a general information exchange ? Actually needed: WKT for time 10
- 12. Operations Basic functions Operating only in the time dimension e.g. Simple queries, Boolean operations, ISO19108-Functions Spatio-temporal analysis Integrated processing in the spatial and temporal dimension e.g. ISO19108-Feature Successions 11
- 13. Relative Position 12
- 14. ISO19108 – Feature Successions Feature Substitution Feature Division Feature Fusion May be derived trough a combined use of temporal and spatial operations 13
- 15. Implementation with PostgreSQL Why PostgreSQL? User defined base type in PostgreSQL Standard compliance and far-reaching possibilities in configuration Spatial functionality provided by PostGIS -> OGC compliant Current capabilities: The six object types Exemplary the three types of reference frame Various basic functions Examples for spatio-temporal analysis 14
- 16. What are the predecessor and successor associations between several countries? Shapefile: W EIDEMANN, N. B.; DOREEN, K.; GLEDITSCH, K. S. (2010): The Geography of the International System: The CShapes Dataset, http://nils.weidmann.ws/projects/cshapes/shapefile (2013-03-07). 15
- 17. For each time step: In which state did the most tornados take place? Shapefile: NATIONALATLAS.GOV (2011): nationalatlas.gov – Map Layers, http://nationalatlas.gov/maplayers.html (2013-03-07). 16
- 18. Perspective Purpose: From the proof-of-concept to the first release • Extend the range of functions • Decent documentation • Extensive testing • Validation of the concept Particular: Managing the various reference frames Syntax for the information exchange User defined reference frames Documentation with Doxygen 17
- 19. Peter Broßeit Peter.Brosseit@mailbox.tu-dresden.de Masters programme ‚Geoinformation Technologies‘ 18