# Shared Flashcard Set

## Details

GIS (MIdterm Study)
Flash Cards for Midterm
43
Geography
02/26/2012

Term
 What are the 6 main things that GIS does with data?
Definition
 1. Collect Data2. Store Data3. Maintain (Edit) Data4. Analyze Data5. Output Data6. Distribute Data
Term
 What company created GIS?
Definition
 ESRI
Term
 What are some other GIS Programs? there are 5 of them
Definition
 1. Geomedia2. IDRISI3. Mapinfo4. Autocad Map5. GRASS
Term
 What is the question you have to ask yourself when using GIS?
Definition
Term
 What do coordinate systems consist of?
Definition
 -Latitude-Longitude -Spherical Coordinates
Term
 What does DD stand for?
Definition
 Decimal Degrees
Term
 What does DMS stand for?
Definition
 Degrees Minutes Seconds
Term
 what is the equation for getting DMS (Degrees Minutes Seconds) to DD (Decimal Degrees)?
Definition
 divide the amount of minutes or seconds you have by 60.Ex. lets say you are given: DMS 74 45' 13" W, you would then divide 45 by 60 and get .75, or 75 minutes or seconds. which mean that:DD: 74, 75 W
Term
 what is nominal data?
Definition
 non-numeric, non ranked (Ex. Name)
Term
 What is Ordinal Data?
Definition
 Ranked, No magnitude (ex. 1st, 2nd, 3rd)
Term
 What is Interval Data?
Definition
 Magnitude of difference among your entities, can have an arbitrary 0.
Term
 What is Ratio Data?
Definition
 When you have an absolute 0, when zeo means nothing (for example, where there is no population)
Term
 What is Vector Data?
Definition
 Network of points, lines and polygons. this includes:-Point-Nodes-Lines (which are 1-D)-Polygons (which are 2-D)-Cube (3-D)
Term
 What is Raster Data?
Definition
 a grid of uniform sq. cells,each of which has a value. Ex. Photography, Land cover maps, continuous data.
Term
 What is Discrete Data?
Definition
 entities are separated by boundaries or space
Term
 What are some examples of Continuous Data?
Definition
 -Temperature-Elevation-Rainfall
Term
 What is Topology?
Definition
 Study of geometric properties that do not change when forms are bent or stretched.This Includes: -Intersection between lines-Adjacency: polygons are adjacent to each other and when points are within polygons-Containment
Term
 What is a .mxd file?
Definition
 its a MAP FILE only works when it has (.mdb, .gdb, .shp)
Term
 What are .mdb and bdb files?
Definition
 these are GEODATABASES which include vector and raster.
Term
 what are .shp?
Definition
 these are SHAPE files
Term
 what are .shx
Definition
 these are INDEX files
Term
 what are .dbf?
Definition
 these are DATABASE files (found in the spread sheet)
Term
 What is geodesy?
Definition
 measuring shape of the earth ellipsoid, also refereed to as an oblate spheroid
Term
 What are map projections?
Definition
 representations of the 3-dimensional Earth on a 2- dimensional surface.
Term
 which 2 types of projections are considered to be "OK"
Definition
 CONFORMAL AND EQUIVALENT
Term
 What is an Conformal Projection?
Definition
 The Mercator Projection is a conformal projection with correct shapes for landmasses but great exaggeration of size near the poles.
Term
Definition
 -North American Datum 1927-Based on the Clarke 1866-Based on one station in Kansas
Term
 What are some other GIS Programs?
Definition
 -GeoMedia- Intergraph, Remote Sensing -IDRISI- Clark University, inexpensive, runs on old computers-Mapinfo- (Troy, NY)- Minor player-AutoCAD Map- Add-on to AutoCAD-GRASS- Army Origin
Term
 What are some examples of attributes?
Definition
 Name, size, physical attributes, collected rainfall
Term
 Cartographic Spaghetti
Definition
 lines that do not have topology
Term
 Cylindrical Projection
Definition
 •good for world maps
Term
 Conic Projection
Definition
 good for mid lat regions
Term
 Planar/Azimuthal Projection
Definition
 good for polar!
Term
 Gnomonic
Definition
 light in center of globe
Term
 Strereographic
Definition
 light at far side of globe
Term
 Orthographic
Definition
 light infinitely distant
Term
 Datum
Definition
 Ellipsoid, known points benchmarks
Term
 what did Eratosthenes discover?
Definition
 • Knew that the sun was overhead in Syene cause it went directly down a well• He then traveled to Alexandria and noticed that there was a slight shadow and was different from syene• He was able to dertermine the circumference of the earth of 40705 km which is very accurate but not exact.
Term
Definition
 -North American Datum 1983-Has multiple benchmarks
Term
 What is UTM?
Definition
 -Universal Transverse Mercator-Has 60, 6 degree zones-Never Negative, the center of the zone 500,000m east of the false origin. -For the southern hemisphere works by working your way down. Starts with 10 million at the center line and as you go down and will go to approx 3 million.-Error is usually 1 to 10,000 off.
Term
 What is the State Zone Plane?
Definition
 -Coordinate system based on a standard line running through a small zone. -False origin: S and W. -In feet, opposed to to meters. -WE are in New York East.
Term
 What direction are trending zones that are involved in Lambert Conformal?
Definition
 East-West
Term
 What direction does trending zones go in TRANSVERSE MERCATOR
Definition
 North-South
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