intro to GIS Flashcards
What is a GIS
organized collection of computer hardware, software, geographic data, trained humans and infrastructure to collect, manage, displace and analyze spatially-referenced data for problem solving
goal of a GIS
- enhance geographic data to make more meaningful to end users
- extract quantitative info from maps, image and tables
-transforms data to info, knowledge, evidence and wisdom
data
-observations/measurements obtained from the real world
- raw numbers without any processing
-data needs to be processed and prsented to produce useful info
-metadata
- spatially reference data has location included
accurate vs precise
- accuracy: how close a measurement is to the true/accepted value
-precision: how close measurements of the same item are to each other
why is spatial location important?
delivery of physical services such as postal, utility, etc..e
geospatial reference system
identifies locations on the earths surface
3 main categories of reference systems in GIS systems
-census geog: postal codes, dissemination areas
-geocoding: postal address/codes, coordinate geometry
-spherical and planar coordinates: lat/lomg, UTM
3 perspectives (general functionalities) of a GIS
- database view
-map view - model view
database view
geographic database
(geo database) - describes the world in geographic terms
map view
set of intelligent maps that show features and feature relationships on the earths surface - (geovisualization)
model view
set of information transformation tools that derive new geographic datasets from existing datasets - (geoprocessing)
vector GIS
objects: feature
polygons: lakes, forests
lines: roads, powerlines
points: telephone mast, wells
GISystems and GIscience
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