Intro to GIS Flashcards
GIS
Geographic Information System: A system of computer, hardware, software, and people used for entering, storing, and manipulating data
What is the most important component in a GIS?
People
5 Core Components of GIS
People: Develop procedures
Data: Needed, accuracy can affect
Hardware: any device that can be used to access GIS. Processing capacity and storage
Software: Software packaging, database management, GIS
Procedures: Requires well defined consistent methods, to produce correct and reproducible results
Four. Types of Map Projections
1.) Conical
2.) Cylinder
3.) Planar
4.) Miscellaneous
Geodesy
The science of measuring the shape of the earth
Data Input Technique
1.) Full-Length Encoding
2.) Scan a map
3.) Digitize a map
Datum
Reference point for measuring locations on earth
GIGO
Garbage In Garbage Out
Topology
The spatial relationship between two points
Raster vs Vector
- Vector is more complex
- points, lines, and polygons
- need topology
- raster is larger
- topology is implicit
- equal grids
General Data Sources
Federal: USGS
State/Local: Town of Durham
NGO: Nature Conservancy/ /Audobon
Private: Microsoft
Coordinate transformation
- also known as registration
- transfering 2D to another 2D map so that the points line up
Types of Digitizing
1.) Manual
2.) Heads-up
3.) Scan
7 Map Characteristics
1.) Author
2.) North Arrow
3.) Scale Bar
4.) Legend
5.) Source
6.) Figure
7.) Title
Scale
- if the features are large(a map of Boston), it is a large-scale map(1:24000)
- if the features are small(Map of Asia), its small scale(1:100,000)
Map Projection
the transfer from a 3D globe to a 2D map
Forms of Distortion
1.) Distance
2.) Direction
3.) Area
4.) Shape
5.)Scale
What is the shape of the earth?
Geoid
