BOT/GEOG 3150: Survey of Remote Sensing Applications – Review for Final Exam
Review Questions for Final Exam
The final exam will be given on Tuesday, May 9 from 10:15 – 12:15.
As stated in the syllabus, the final exam is worth 20% of your grade (same as the
midterms). Exam questions will include problem solving, short answer, and short discussions based
on the lecture and the readings. Questions will focus on new material that we have covered since
the last exam but you will also be required to draw on general information from earlier in the
semester. The questions given in this review sheet cover the topics that might appear on the exam,
including things you should know from the entire semester. Bring your calculator!
Anything not covered in class before the exam will not be on the test.
General Concepts from Semester
1. Understand the primary advantage(s) of aerial photography vs. satellite-based multi- and
hyperspectral remote sensing and vice versa.
2. Be able to draw the typical spectral reflectance curves for green vegetation, soil, and water
and to label the main spectral regions (R,G,B,NIR,MIR) corresponding to the parts of the
curve.
3. Given some problem in one of the application areas we covered (e.g., planning,
archaeology, geology, land cover mapping, etc.) be able to suggest a type of remote sensing
(e.g., aerial photography, multi- or hyperspectral RS, active RS, etc.) and general
methodology that might be appropriate for solving it.
4. Be able to discuss the fundamental challenge of remote sensing (distinguishing different
materials) and why it is important to consider using many types of remotely sensed data or
other data to solve this challenge.
5. Be able to define spatial, spectral, and temporal resolution.
6. If I give you the spatial resolution of an instrument, be able to calculate how many pixels
will cover some area of given size. This includes correctly converting to common units!
Marine and Coastal Remote Sensing
1. Why is estimating ocean chlorophyll content important, and how can satellite remote
sensing contribute?
2. What factors contribute to ocean productivity, and how does satellite remote sensing
contribute to productivity modeling? Why do we often need to included modeling when we
study ocean processes?
3. How can remote sensing contribute to fisheries management?
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BOT/GEOG 3150: Survey of Remote Sensing Applications – Review for Final Exam
4. Why can ocean turbidity affect estimates of ocean chlorophyll and productivity?
5. What factors affect the spectral properties of turbid water?
6. What is the SeaWiFS satellite used for primarily?
7. What are some important applications of satellite remote sensing in the coastal zone?
8. How does El Nino affect productivity in the Eastern Pacific, and how can we monitor this
with remote sensing (see reading)?
Remote Sensing for Agriculture
1. How does plant reflectance change as biomass increases? What common spectral index is
used to measure this?
2. What must be true if we are to distinguish two or more crop types using RS?
3. What is the red edge? How does it change when plants are stressed?
4. What happens to the temperature of a leaf when it closes its stomata?
5. Be able to define precision agriculture, and give some examples of how remote sensing can
contribute. What are some advantages of precision agriculture?
6. What is one way to define forage quality? How can we use RS to detect leaf nutrient
content?
7. What is phenology? How can we use it to map cheatgrass distribution?
Atmospheric Applications of Remote Sensing
1. When were the earliest satellites launched and what was their value for weather remote
sensing?
2. What is a “full disk view” and why is it valuable for weather forecasters?
3. Be able to describe differences between polar orbiting and geostationary satellites. What
are advantages and disadvantages of each?
4. What do meteorologists use visible wavelengths to study? What are the thermal infrared
wavelengths used for in weather studies?
5. Why is the altitude of cloud tops important to weather forecasters and how do they use
satellite data to estimate this property?
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BOT/GEOG 3150: Survey of Remote Sensing Applications – Review for Final Exam
6. In general, how can remotely sensed data be used to estimate the concentration of
atmospheric constituents?
7. What is the difference between stratospheric ozone and tropospheric ozone for humans?
8. Why might it be advantageous to “look up” from the ground rather than “looking down”
from space for atmospheric studies using EMR?
9. What are aerosols?
Radar and Lidar Background and Elevation Mapping
1. Why can active remote sensing be used at night and passive can’t?
2. What wavelength region(s) does radar use? What wavelengths to Lidar use?
3. What are some advantages and disadvantages of radar remote sensing?
4. Define backscatter and depression angle.
5. What is the difference between specular and diffuse (Lambertian) reflectors and how would
each appear on a radar image? What is a corner reflector?
6. What’s the difference between “real aperture radar” and “synthetic aperture radar”?
Which is more commonly used and why?
7. Do most radar look straight down (nadir) or off to the side (oblique)? Why?
8. What are the two general strategies for mapping elevation with radar data? Which is
typically more precise?
9. How might you use radar to study volcanic activity or glacial movement?
10. Why does lidar typically produce more precise elevation surfaces than radar?
11. Be able to list 2 or 3 applications of lidar and how it would be used.
Thermal Remote Sensing
1. What wavelength region does thermal remote sensing use?
2. Be able to describe the greenhouse effect in terms of EMR interaction with the earth and
atmosphere. How is this relevant to thermal remote sensing?
3. Which commonly used satellites have thermal bands?
4. As the temperature of an object increases, what happens to the amount of energy given off
and the wavelength of emitted EMR from that object?
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BOT/GEOG 3150: Survey of Remote Sensing Applications – Review for Final Exam
5. Define emissivity. What is the emissivity of water?
6. What is the difference between kinetic and radiant temperature of objects? Which do you
measure with thermal remote sensing?
7. What do you need to know about an object to calculate its kinetic temperature from a
thermal image?
8. Why is thermal remote sensing useful for mineral mapping? Why is it not so useful for
vegetation mapping?
9. What is a thermal lag and how could you use thermal lags to distinguish materials with
remote sensing?
10. Describe some factors that complicate the interpretation of thermal images.
11. Be able to describe a few common applications of thermal remote sensing.
12. What is consumptive water use and how does remote sensing in general and thermal
remote sensing in particular contribute to its estimation?
13. What is evapotranspiration (ET)?
14. Be able to write the energy balance equation and describe its components. Where does
thermal remote sensing fit in?
15. Based on your understanding of the energy balance equation and thermal remote sensing,
what would you expect to happen to the thermal signature of a crop if it suddenly became
water stressed?
16. How is thermal RS useful for volcanology or earthquake prediction?
Active Remote sensing for Archaeology (if covered in class!)
1. Describe some ways that you could use radar data from the surface (not below ground) to
identify archaeological sites.
2. Why might radar data be useful to researchers looking for archaeological sites in Peru, for
example? How about in the Sahara desert?
3. In general, how does ground penetrating radar (GPR) work? What causes a return
(backscatter) when you are using ground penetrating radar?
4. What is the ideal soil situation for GPR studies? What is the effect of soil water on GPR?
5. What are some reasons for using GPR rather than just excavating an archaeological site?
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BOT/GEOG 3150: Survey of Remote Sensing Applications – Review for Final Exam
6. Describe how you would design a GPR study (site condition, transect spacing, wavelength
trade-offs, etc.)
Global Change
1. Be prepared to discuss some application of remote sensing to global change issues as
presented by your classmates. This would be a very general, non-technical discussion.
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