gi science spatial data modelling
DESCRIPTION
GI Science spatial data modelling. Dr Nigel Trodd Science and the Environment Coventry University. Aim & objectives. To understand the process of building a digital representation of reality to characterise reality (as a spatial concept) - PowerPoint PPT PresentationTRANSCRIPT
GI Sciencespatial data modelling
Dr Nigel Trodd
Science and the Environment
Coventry University
Aim & objectives
To understand the process of building a digital representation of reality
• to characterise reality (as a spatial concept)• to identify the process of modelling geographical
phenomena• to identify & exemplify entitation & data modelling• to identify vector and raster data & their data
structures
Building GI models
I am a Geographer
I model places & spatial phenomena
I am a Computer Scientist
I model information in a database
GI Science = Geography + Computer Science
How can we store geographical data in a computer?
the real world is complexandcomputers are very simpleandcomputers need us to model the geography for them.
How do we model the real world in a computing environment ?
from reality to spatial data structures
in
1.. 2.. 3.. 4 (easy) steps
1. from reality to geographical phenomena
2. from geographical phenomena
to spatial entities
3. from spatial entities
to spatial data models
4. from spatial data models
to spatial data structures
1. from reality to geographical phenomena
2. from geographical phenomena
to spatial entities
3. from spatial entities
to spatial data models
4. from spatial data models
to spatial data structures
terminology overload...
... there’s more
How do we view reality?
1. from reality to geographical phenomena
Values at different places• Continuous variation – biomass, elevation, SST
Points and edges with associated data• Discrete objects - house, pipeline, river,
coastline
1. from reality to geographical phenomena
2. from geographical phenomena to
spatial entities
the famous 5ive...pointslinesareas
networks & surfaces
Geometry
Topology
Concepts of geography
3. from spatial entities
to spatial data models
object-based
field(or layer)-based
wakey wakey
… here comes the
easy bit
vector & raster
4. from spatial data models
to spatial data structures
I am NOT a Geographer
I am NOT a Computing Scientist
I am a GI Scientist.
I model.
I am crude.
I use basic IT.
I work.
Summary
I am a GI Scientist. Are you?
• outline the art of building a digital
representation of reality.
• identify & exemplify 5 spatial entity types.
• explain the elements of a spatial data model.
• identify differences between vector and
raster data & exemplify their data structures.