GEOG363 EXAM 2 Flashcards Preview

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Flashcards in GEOG363 EXAM 2 Deck (60):
1

majority of cost and time in building a GIS

data preparation/building the database

2

on screen digitizing

"heads up" with vectors

3

what will happen to digitizing errors as you increase the scale of the map

the error will increase proportionate to the increase in map scale

little errors in the large scale can mean huge scales in small scale maps

4

name 5 types of positional errors

1. undershooting/overshooting nodes
2. open polygons
3. missing nodes
4. self intersecting lines
5. sliver polygons

5

what does snap tolerance do?

it snaps undershot nodes to lines through buffers

6

what to options do we have to correct positional error

1. redraw
2. choose master boundary

7

registration

when layers spatially coincide

8

name 2 examples of post-processes

1. smoothing
2. spline - interpolates curves to reduce jaggedness of edges

9

name 3 sources of rasters

1. scanned maps
2. remote sensing
3. statistical surfaces

10

what is the difference between an image and a photograph

photographs are specific to images that are on film

11

unreferenced raster refers to...

when coordinate values to position an image are missing

12

regular raster distortion (3)

image is out of:
1. scale
2. shift
3. rotation

13

irregular raster distortion (2)

1. terrain
2. flight conditions

14

what do we call fixing regular and irregular raster distortion

orthoimagery

15

affine transformation

preserving the parallel nature of lines and ratio of distances

16

collinear

any number of points can be said to be collinear if a straight line can pass through them all

17

3 types of affine transformation and define them

1. translation (sliding)
2. rotation
3. dilation (scaling)

18

what kind of distortions are affine transformations good for?

regular

19

what kind of distortions are higher order polynomials good for?

irregular

20

RMSE

root mean square error

a measure of precision between true and computed coordinates of points

NOT ACCURACY

21

nearest neighbor

assigns output cell value from nearest corresponding input cell

22

bilinear interpolation

uses nearest cell and next closest 3 to get a weighted average

23

what does georeferencing develop in order to transform all cells of a raster

equations

24

difference between a database and DBMS

DBMS allows access and understanding of data

25

name 5 things DBMS can offer that databases cannot

1. locking
2. rights
3. views
4. back ups
5. monitoring

26

what does n-tier architecture describe

allows users (web users [upper tirer]) to access data (in a database [bottom tier]) to interpret data without accessing the data itself

27

how can multiple tables be joined?

through a common unique ID attribute

28

what kind of algebra is used in query language?

relational algebra

29

name and define 4 different hings that can be done with relational algebra

1. intersect - in both tables
2. union - add two tables
3. difference - take away from one table
4. join - link tables through a key attribute

30

SQL and define

Structured Query Language is a special programming language used to manage data in a RDBMS

31

Primary key

one column that contains a unique value for every row in the table

32

what is something primary keys can be used for

cross referencing two different tables - here it acts as a foreign key

33

3 rules of tables

1. cannot be 2 identical rows
2. there must be a primary key
3. the primary key may not contain any null values

34

functional dependency

an attribute is functionally dependent if it is determined by the value of another attribute

35

local spatial operations

one input for one output

36

neighborhood spatial operations

local and nearby input influence output

37

global spatial operations

entire input layer is used to determine each local output

38

dissolve operation

features with same attribute value are merged

creation of aggregated polygons

39

2 most important tools of GIS analysis

buffers and overlays

40

how were overlays done back in the day

with transparent copies

41

father of GIS

Dr. Roger Tomlinson

42

overlays combine data to do what two things?

join attributes or filter out data

43

what 3 things must be done before working with overlays?

1. georegistered
2. same resolution
3. functionally related

44

what will overlays that combine different vector geometries result in?

a layer with a lower dimensional geometry

45

what are network structures used for?

to represent features such as roads, pipelines, rivers, etc

46

name 2 things network analysis can be used for

route selection
resource allocation

47

geocoding and its problem

linear referencing of addresses along road features

NOT ALL BUILDINGS ARE OF EQUAL SIZE OR SHAPE

48

gazetteers

place name directories that contain spatial information and feature type

pizza shop is here

49

ontology

classification of feature types

50

what does reclassification do to new values

makes the resulting class more generalized

51

MAUP and define

Modifiable Areal Unit Problem

Changing the size or shape of an object can alter the values in the classes

52

natural break classes

minimize intraclass differences and maximize interclass differences

53

spectral signature and example

certain things in a remote senses photograph have a specific color

EG water is blue

54

georectification

adding control points to photos to make them accurate

55

transit costs

weight used to make models that use attribute data to weigh distances

56

equal area

take x classes and make sure that they have the same area

57

what do thematic maps emphasize?

attributes

often only one or a few

58

what do reference maps emphasize

features

often many features

59

ecological fallacy

to assume that a generalized statistic refers to an individual within a population

60

name 3 types of vector buffera

simple
compound
nested