Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
50 Cards in this Set
- Front
- Back
Geographic Inquiry Process
|
Ask, Acquire, Explore, Analyze, Act on Geographic Knowledge.
|
|
What is GIS
|
A collection of computer hardware, software, and geographic data for capturing, managing, analyzing, and displaying all forms of geographically referenced information
|
|
Three Views of GIS
|
Database, Map, Model
|
|
What can GIS do?
|
Caron still queefs at dp
Capture,Store,Query,Analyze,Display, Present |
|
Why is GIS > Google Earth
|
GE doesn't analyze, only displays.
|
|
Are features static?
|
No time changes shit all the time
|
|
3 parts of ArcGIS
|
ArcCatalog ArcMap and ArcToolbox
|
|
ArcMap
|
Display application. Performing map based tasks
|
|
ArcCatalog
|
Fuck with your data.
|
|
ArcToolbox
|
Geographic processing functions. Data management, analysis and conversion
|
|
Why is the earth not a perfect sphere?
|
It rotates on its axis pulling it to the equator so its a spheroid
|
|
Steps in a Projection
|
Eath to Geoid to Datum to Projection to Coordinate System
|
|
What is the geoid elipsoid
|
it is the combination of the spheroid and the surface on the earth. This geoid elipsoid is how we have a clue of what to do projections based on
|
|
geoid
|
accounts the surface differences on earth
|
|
datum
|
reference points, extremely accurate
|
|
what is a datum on earth?
|
National geodetic survery points
|
|
Why do we need projections
|
because when you move from a round object to a flat object you are going to fuck up parts of the flat object
|
|
What are the 4 types of projections
|
cylindrical, conical, planar and other
|
|
types of contact?
|
transverse- cylindar on its side
oblique- at an angle normal- cylindar up and down |
|
types of contact?
|
tangent and secant
|
|
how do you pick a projection?
|
look at its purpose, its extent or area of focus its orientation: whether is it very EW or NS its latitude range and what other coordinate systems apply
|
|
two types of coordinate systems?
|
geographic and projected
|
|
what are unprojected coordinate systems projected in?
|
degrees because its the earth...period.
|
|
what are unprojected coordinate systems projected in
|
anything
|
|
are gcs's good for mapping
|
no
|
|
if you are off by a degree how far off are you?
|
110 km at the equator...it sucks
|
|
what is every map projection based on?
|
a GCS
|
|
what does every GCS include as staples for factors?
|
datums
|
|
Do projections have datums?
|
yes
|
|
What would be the most common coordinate systems for wisconsin?
|
UTM, State Plane and Wisconsin Transverse
|
|
Advantages of UTM
|
covers large areas of earth, it is a world wide system
|
|
disadvantages of UTM
|
states can span more than 1 zone.
|
|
What does every data set require in terms of a complete description of spatial reference?
|
GCS/Datum...Projection (if used)...storage units...domain (max and min x and y values)....resolution (x-y precision)
|
|
Managing CSs three typical operations
|
examine the layers CS information, define a CS for a layer with unknown or wrong CS and then convert it.
|
|
how to define a cs
|
in arccatalog or arctoolbox
|
|
how to project a cs
|
arctoolbox or arcmap
|
|
what is a larger scale map? 1:5000 or 1:5000000
|
1:5000
|
|
what is a smaller scale map 1:5000 or 1:5000000
|
1:50000000
|
|
what is a feature class
|
collection of similar objects stored as a single unit
|
|
feature classes can share many geometry features true or false
|
false idiot.
|
|
What are the two data components?
|
data and vector
|
|
vector components
|
Vertex, node, arc, line, points, polygon
|
|
raster
|
grids and pixels
|
|
Difference between the sources of data in vector and raster?
|
vector:aerial photos digitized rasters: TINS figure it out
|
|
when is vector best when is raster best
|
vector is more precise in its shape and position of features whereas raster is great at showing ever changing variables.
|
|
Spaghetti vs Topologic
|
spaghetti just kinda sucks, there aren't really rules and it can come out shitty. Topologic...everything has to make sense and be clean and its great but more time consuming
|
|
Why is topology important
|
it looks better, it can be projected in different ways, and its good?
|
|
Topology rules: gaps and overlapping
|
can't happen
|
|
Topology rules: containing a point or feature class
|
gotta happen entirely
|
|
Topology rules for lines
|
can't overlap, or intersect, be a single part
|