Database
- record (all info about a feature)/ field (category of info)/ value (individual number)
-primary key (the one you are working in) vs secondary key
related based on ID
what does relational database refer to
- each subject has its own table
- tables can be related
Advantages of database (5)**
- security (admin access vs user)
- error checks built in
- data independent from software
- easy to update
- minimal redundancy
- simple analysis (sort/search/query)
Spatial entities
- points
- lines
- polygons
- surface (aka field) ex. contours
spatial data sources
base maps
thematic maps (inventory)
images
field (GPS, roadeng)
Spatial data modelling
Real world
Conceptual (discrete objects or continuous variable)
Logical (GIS)
- vector: spatial = points lines pgons, attribute: data table
- raster: spatial = grid of pixels, attribute: values in pixels
-
can raster model networks?
no. networks have to recognize intersections
what is metadata?
data attached to data that describes things like datum, projection, resolution etc.
Data Input
- build and maintain GDB
- buy and import
- heads up digitize
paper - digital
digitize
scan
fix errors
topology
shared geometry of features. 3 relationships. adjacency, containment, connectivity (how lines are connected).
What are the geometric transformations?
for combining GIS maps
1) edge matching
2) rubber sheeting
projection or datum must be the same. important to update
Types of analysis
vector:
-query
-math calc/ summarize/ relate or join tables
-spatial (buffers, overlays, merge, dissolve)
raster:
-reclassify (simplifies data into classes. logic(0,1)
-calculator ( 2+ layers for combining logic layers) determine change
-surface (contours, slope)
- buffer by euclidiean distance and reclassify***
Output cartography
DESIGN
- concept b4 comp
- hierarchy with harmony
- simplicity from sac.
- max info min cost
- emotions
Organization / ppl
- tech
- analyst
- manager
Definition of GIS
A spatial database that associates attribute information with geographic points and areas.
Components
- computer system (Hardware, OS, GIS + others)
- geog. data (attribute[pixels(raster) data table (vector)] spatial data)
- functions
- org. and ppl
