SECTION A                                     REMOTE SENSING                        (80 MINUTES)

Answer FIVE of the following questions (all are equal in value):

Question 1

Draw a diagram of the EM spectrum, showing the visible, gamma ray, radar, near infra-red, ultraviolet, thermal infra-red and microwave regions. Give the wavelengths for the visible part of the spectrum. Discuss how interactions between the electromagnetic spectrum and the atmosphere determine which wavelengths can be used for particular purposes.

Question 2

Draw a sketch of the absorption spectrum for healthy vegetation and indicate  the approximate location of Landsat 8 bands 2-7 (label each). Explain why leafy plants produce different reflectance values in different parts of the electromagnetic spectrum, and what causes the difference between the reflectance signatures for healthy and unhealthy vegetation. Write down the formula for NDVI, and explain why this ratio is used for the analysis of vegetation cover.

Question 3

For a Landsat 8 image, give the bands in the order RGB (if relevant) that correspond to:

A true colour image

An infrared image with red as the ‘red edge’

A grey scale image showing the maximum contrast for open water The bands used to calculate an NDVI image

Question 4

Discuss supervised and unsupervised classifications, including how they are performed and their relative advantages and disadvantages

Question 5

Explain the difference between true north, magnetic north and grid north Question 6

What is a DEM? Discuss the two main remote sensing techniques used to construct DEM’s, including the wavelengths at which they operate, how the  data is collected, and the resolution of the images. Give examples of how the images obtained can be used.

SECTION                                         B GPS                                  (20 MINUTES)

Answer TWO of the following questions (all of equal value):

Question 1

List the three types of GPS, how they differ in their modes of operation, and their approximate horizontal and vertical accuracies.

Question 2

Why are there multiple datums, even for the same place on Earth? What are the main Australian datums? And why is it important that different layers of data in a GIS share the same spatial reference system?

Question 3

Explain the principles of global positioning using satellites, including the factors that affect the accuracy of a location (you must use a sketch to illustrate your answer).

Question 4

Explain what GDA2020, WGS84, GDA 94 and AGD66 are, including the differences between them, and the typical difference (in meters) between locations obtained using each.

SECTION C                                            GIS                                        (20 MINUTES)

Question 1 (10 minutes)

Answer TWO of the following questions:

1.  Describe the difference between raster and vector data, giving examples of each and illustrating with sketches.

2.  Discuss the concept of scale, including working scale, in GIS, and how scale and location accuracy are related; use sketches to illustrate your answer

3.  What is georeferencing? Explain one way you can georeference an image

Question 2 (10 minutes)

La Trobe University has employed you to assess the extent of flooding likely across the Wildlife Sanctuary at the Bundoora campus, and for this you need to do a GIS analysis. List at least 4 sets of data you would use in your GIS study, and where you would obtain these. Describe how you would determine the extent of flooding using this data