GIS

Question 1

Define the two types of data that you can obtain:

Answer 1

1. Vector Data
2. Raster Data

Question 2

What are the three types of vector data?

Answer 2

1. Point data: (x;y)
2. Line data: a series of point data which join together
3. Polygon data: a series of point data that join together to form a boundary.

Question 3

Define what Raster data is:

Answer 3

Data that is generated from a satellite image or airborne sensors.

It is represented by pixels. Larger pictures - less accurate
Smaller pixels - greater accuracy

Question 4

What is the smallest unit in which raster is measured?

Answer 4

Pixels

Question 5

With raster data, how do you decrease the resolution to ensure quicker transfer?

Answer 5

GIS does this by merging smaller smaller adjacent pixels into larger pixels.

Question 6

Define spectral resolution:

Answer 6

It is used when capturing images of extremely large dimension (e.g. the earth). Spectral resolution refers to the size, spacing and number of bands or frequency ranges captured by a spectral sensor.

Question 7

How many bands of light does a normal camera capture?

Answer 7

3 bands of light

Question 8

True or False:

Spatial data is used for vector data.

Answer 8

True

Question 9

Define spatial data:

Answer 9

• this is vector data
• refers to the position of an object
• co-ordinates (x;у)
• line
• point

Question 10

True or False: Attribute data is used with vector data.

Answer 10

False!!!

Question 11

Define Attribute data:

Answer 11

• this is raster data
• refers to information describing or giving the characteristics of an object

Question 12

Define the 6 advantages of GIS:

Answer 12

1. Allows the display and visualisation of spatial information
2. Allows for the quick collection of data
3. Creates maps with themes to determine relationships
4. Provides high accuracy and allows for prediction and analysis
5. Assists with natural resource management
6. Allows viewing, questioning, understanding, visualizing and interpreting data which reveals relationships, trends and/or patterns of geographic information

Question 13

What does it mean if data is non-spatial?

Answer 13

Data which is not linked to a specific location.

Question 14

What is the difference between non-spatial and spatially referenced data?

Answer 14

Non-spatial data has no link to a specific location whereas data which is spatially referenced is linked to a specific location.

Question 15

In vector data, what are two other terms used instead of “scale”

Answer 15

1. Minimum Mapping Unit
2. Accuracy

Question 16

Can the scale of vector data be changed?

Answer 16

Yes, it can by zooming in and out.

Question 17

What does the accuracy of vector data refer to?

Answer 17

It refers to how closely the representation matches the feature it is supposed to represent.

Question 18

Define Spectral Resolution:

Answer 18

It is used when capturing images of extremely large dimension (e.g. the earth). Spectral resolution refers to the size, spacing and number of bands or frequency ranges captured by a spectral sensor.

Question 19

Look at notes for notes on buffering!!!!

Answer 19

Looked at notes.