Midterm 1

Question 1

Give two examples of software in GIS

Answer 1

Like arcmap, arctoolbox, arccatalogue (the three components of GIS)

Question 2

What is raster data good for?

Answer 2

Continuous data, layers, satellite or orthophoto

Question 3

What are some things vector is good for?

Answer 3

Querys, buffers, watersheds or eyesheds, routing, overlays

Question 4

What is GIS?

Answer 4

Stands for geographic information system

Integrated set of components that operates on spatially explicit data to generate new information and understanding for aiding in decision making

Question 5

What is vector?

Answer 5

Lines with coordinate plus data tables

Question 6

What is raster

Answer 6

Grid of cells (pixels) with values like a spreadsheet

Question 7

What are the three levels of arcGIS?

Answer 7

Arcview, arceditor, arcinfo

Question 8

What are the three dimensions of spacial data?

Answer 8

Time, spatial(discrete or continuous) and attribute(non spatial info about a feature usually stored in tables and may include string or field info- about how it should be displayed)

Question 9

What are the most common prjections used for mapping in bc?

Answer 9

Universal trans mercator UTM

Albers equal area (conical with standard parallels)

Question 10

In arcgis what is datum?

Answer 10

What version of best fit lat and long

Like NAD83 or 27

Datum is “the reference specs of a measurement system, usually coordinate systems horizontal or vertical”

Question 11

In gis Define discrete and continuous data and an example of each

Answer 11

Discrete has definite boundaries like a stream or road.

Continuous varies without steps or boundaries (“infinite” possibilities)

Question 12

Three types or digital capture of gis data?

Answer 12

Scan
Digitize
Keyboard entry

Question 13

The three sources of gis data?

Answer 13

Gis map data (base maps like geobc topo, forest cover maps)
Remote sensing (lidar, satellite, orthophoto)
Field surveys (gps, roadeng, cogo)

Question 14

How does satellite imagery work?

Answer 14

Using energy from the sun, satellite sends beam to earths surface which is reflected back to the satellite sensor and ten beamed tom a recieving station

Question 15

Explain how digitizing works

Answer 15

Using computer program drafting assists, or manually trace in tracing tablet
Can use point mode- tracing points and the computer connects them- or streaming mode- where you literally trace and the computer streams out sets of points
Heads up digitize where you trace with mouse or pen on advanced screens

Question 16

Explains steps of scanning

Answer 16

Generate a raster image by letting computer read a map as an image
Then you vectorize- well, the computer does this
Optionally give spatial references to at least four corners to georeference

Question 17

Two editing processes within gis data?

Answer 17

Detect and correct errors

Update or maintain database

Question 18

What are some errors that can happen with editing?

Answer 18

Sloppy work errors-
Poor tracing
Sliver polygons
Under and overshooting 
Missing or duplicate features

Question 19

What are some types of generalizations

Answer 19

Line smoothing
Weeding coordinates or thinning a line
Combination, selection, omission

Question 20

What is topology?

Answer 20

A way of defining how two features share a boundary

Question 21

What are some other kinds of geometric transformations? Than projection matching

Answer 21

Datum matching
Edge matching
Rubber sheeting

Question 22

List four types pf geometric transformations

Answer 22

Convert projection, datum, rubber sheeting, edge matching

Question 23

What are the 5 concepts to consider in cartographic design?

Answer 23

CHSME

• Concept before compilation- know purpose and audience
• Hierarchy with harmony- intellectual (critical elements), visual (size and location and figure ground relationship)
• simplicity from sacrifice- use generalizations
• max info at minimal cost- have an effective design
• engage emotion- good maps are art

Question 24

What are some non map outputs?

Answer 24

Cartogram- cross between map and diagram
3d resemtations
Animations

Question 25

What is a record?

Answer 25

All of the information about one entity

Question 26

What is a primary key? Secondary?

Answer 26

Primary is the unique identifier that relates to a record
Secondary is the info attached to a primary key record
Eg. Ability to graduate related to tuition payment

Question 27

8 advantages of database?

Answer 27

1. Data is independent of software
2. Simple structure
3. Less redundancy (if design is good)
4. Auto error checks
5. Easy to access to variety of uses
6. Easy to update/maintain
7. Can restrict security on editing
8. Can do basic searches (sorting, querying, searching)

Question 28

What are the two types of fields in databases?

Answer 28

Text/string (name or character)

Numbers (need to be precise, 0s hold paces, count (-) but not decimals)

Question 29

What are three basic types of analysis?

Answer 29

Sorts
Querys
Complexes

Question 30

What are the three parts of a query?

Answer 30

Field name
Relational operator
Value

Question 31

What are complex analysis boolean operators?

Answer 31

And, or, not (for search refining)

Question 32

How are spatial and attribute data linked in GIS?

Answer 32

When attibute data is queried, and when map data is queried

Spatial data is kept in unsees tables
Attribute data is kept in tables also

Question 33

How should tables be linked?

Answer 33

One:one if records match up with one line each
Many:one if destination has many records matching one source line
Not joined if one:many, just highlighted

Question 34

Which tables have primary keys? Secondary?

Answer 34

Destination
Source

They are given different field names though to differentiate, eg. Student number (primary) vs student code (secondary)

Question 35

In GIS data is always brought to the…

Answer 35

Map table

Question 36

Which relationships between tables are joins? Which is not?

Answer 36

One: one and many: one

One: many is not a join

Question 37

What does the term many to one mean?

Answer 37

Many records in the destination table relate to the source table

Question 38

What are the five components of GIS?

Answer 38

Software
People 
Data 
Hardware
Methods