Remote Sensing of the Environment

FINAL: May 1, 2001, Geography 4093/5093

Answer question one (EOS). Then you can choose to answer a total of three questions from Applications and/or Topic. In total you have to answer 4 questions.

1. Earth Observing System (EOS)

a) Name at least two missions (satellites) which are scheduled during the Earth Science Enterprise.

b) What are the main functions of the EOS data and information system?

c) What are Pathfinder data sets during EOS?

2. Atmosphere: Clouds

a) Describe the relation of visible radiance and infrared brightness (temperature) for land, ocean, and clouds (low, medium, and high level clouds). Draw the outline of a typical visible/IR scatter plot and identify the part of the plot corresponding to each class mentioned above.

b) How can you determine the cloud height from IR satellite data?

c) Discuss the difficulties of classifying cloud types in Polar Regions.

3. Atmosphere Application: Clouds

What instruments/sensors would you use to detect cloud amount and cloud types from space. Your objective would be to make an annual cloud statistics for the entire Earth that would resolve the seasonal variations. Key words: cloud reflectance, temperature, optical depth, ice clouds, polar night, absorption.

4. Cryosphere: Monitoring

a) Describe a method to measure the extent of snowmelt on the Greenland ice sheet.

b) What sensor combination would you choose to monitor the snow in the Rocky Mountains from space?

c) Why is snow mapping with SAR not possible in the Arctic during winter?

5. Cryosphere Application

You are trying to determine the seasonal and interannual variation of the total snow cover on the Earth. Compare and contrast the effectiveness of four major types of sensors (visible, thermal IR, passive microwave, and SAR) for this mission (key words: cloud cover, spatial coverage and resolution, wet snow, dry snow, albedo, polar night).

6. Hydrosphere

a) Describe two satellite methods to measure surface wind speed from space.

b) How can ocean currents be measured with satellite remote sensing?

c) Can you derive chlorophyll concentration in the Arctic during the polar night - why?

7. Hydrosphere Application

Describe methods to derive the sea surface temperature (SST) with thermal infrared (TIR) and passive microwave (PM) satellite data, and contrast the two methods (key words: emissivity change due to wind in PM, accuracy, clouds, atmospheric window, spectral channels).

8. Biosphere: Estimates of biomass, & Geological hyper-spectral measurements

a) The Normalized Difference Vegetation Index (NDVI) uses two wavelength regions - name them.

b) Can you derive a mushroom density (assuming you have the spatial resolution) with NDVI - why?

c) Describe the method to classify minerals at high spectral and spatial resolution with remote sensing data.

9. Biosphere and Geological Application

You have a Landsat TM image from the Alps. Part of the image shows a forest and part of the image shows bare rock surface with no vegetation. How would you assess the stress level due to air pollution of the forest, and how would you classify the different rock types based on the Landsat TM channels. Key words: VIS, NIR reflectance, leaf structure, water absorption bands, thermal inertia.