GIS Flashcards
Wat kan GIS?
Het kan geografische gegevens opslaan, analyseren en visualiseren
en informatie.
Geographic Information System (GIS)
is een
computergebaseerd hulpmiddel dat ruimte onderzoekt
relaties, patronen en trends in de geografie.
The 4 main concepts that make up any GIS are:
1) Data entry: to create geographic data.
2) Data management: to manage it in a database.
3) Spatial analysis: to analyze and find patterns.
4) Cartography: to display it on a map.
de 5 elementen van GIS
- hardware
- software
- (geographic data)
- rules and procedures
- people/ organisation
de drie data types (ESRI)
Vector, Raster en storage
Workflow GIS
Spatial problem
↓
Data input
↓
Data maintenance
↓
Data analysis
↓
Data output
↓
Presentation
Vector model
A spatial model built out of POINTS,
lines and polygons
* Each point is a coordinate pair (X,
Y)
* (Meta)data is attached to these
points or features
Raster model
pixels!!!
- A spatial model in which geoinformation is represented as a grid
of X en Y coordinates - Each cell has a value attached to it
wat is belangrijk als je gebruikt maakt van een vector model
schaal (engeland)
analogue data sources
Paper maps
* Tables
* Printed aerial photos
* Ideas
digital data sources
Maps
* Digital aerial photos
* Satellite / aerial images
* Loggers / sensors
* GPS
Data acquisition
is the process of converting real-world signals to the digital domain for
display, storage, and analysis. Because physical phenomena exist in the analog domain,
i.e., the physical world that we live in, they must be first measured there and then
converted to the digital domain.
spatial questions
- Where is…? (-> location)
- Where are high densities of…? (-> pattern)
- Where are mountaintops melting? (-> trends)
- Where is a camping near…? (-> conditions)
- If I park here how far am I from…? (implications)
dissolve (tool)
het is een tool dat meerdere polygonen samenvoegt
de basis van een veld
error
– Flaw in the data
bv. typos → enter (y,x) instead of (x,y)