Old Remote Sensing Exam Questions

Example SURE 339 Exam Questions

In extracting information from imagery, the analyst requires explicit (or formal) knowledge of the landscape. Why?
Discuss the concept of transparency as it affects the commercial remote sensing community. What is shutter control?
Describe the two important remote sensing relationships defined by the energy balance equation.
Temporal effect (or spatial effect) influence spectral response patterns. Explain and give a clear example.
Energy of a quantum is given as Q = (hc)/l. Describe the significance of this property as it applies to remote scanning. What is the significance of Wien's Displacement Law as it applies to remote sensing?
What is the difference between an active and a passive sensor? Give an example of each.
Describe the cause and effects of Rayleigh scatter. Describe the cause and effects of nonselective scatter. Describe the important consequences that scattering has on remote sensing.
What is refraction and its causes? Describe the importance of atmospheric absorption on the selection of the remote sensor. What is absorption?
What is the difference between a specular and diffuse reflector?
What is the difference between spectral and spatial resolution? Describe radiometric resolution. Describe how resolution is measured in an image.
Films are described by their spectral sensitivity. Describe and give an example.
What is the characteristic curve and why is it important?
What is the difference between band interleaved by line (BIL) and band sequential (BSQ) data formats? Describe the data format band interleaved by pixel (BIP).
Identify and describe two of the advantages of multispectral scanner data over photography. What is the difference between the across-track and along-track multispectral scanner?
Identify the advantages of a linear scanner array over mirror scanning systems. What are the disadvantages of a linear scanner array? What are the advantages of pushbroom scanning over whiskbroom scanning?
What is a diffusion grating?
Define dwell time.
What is the instantaneous field of view? What are the advantages of a large IFOV.
In image interpretation, texture is used to identify features. What helps determine the texture within an image? Describe how shadow affects image interpretation.
Describe the typical problems the image interpreter addresses when delineating observed regions on imagery.
Describe how image acquisition was performed with the Corona spy satellite system.
Describe the process by which Landsat multispectral data are captured. Why is the repeat cycle different between Landsat-1, -2, and -3 as compared to Landsat-4 and -5? What configuration was employed with Landsat-4 and -5 to increase the repeat cycle? The Landsat MSS image scene initially contains skew. What is it and what are the effects on the image format upon removing the skew effect?
What was the RBV system on Landsat-1, -2, and -3? How was the image captured? What was the advantage of the RBV sensor over the Landsat MSS system? Describe how the RBV camera system on Landsats 1 and 2 are different from that used in Landsat 3.
Landsat's Thematic Mapper (TM) represents an upgraded MSS image. How is it better? The TM scan acquires data in both directions, whereas MSS scans were acquired in only one direction. How did this affect image acquisition?
What are the objectives of Landsat 7?
Describe SPOT's off-nadir viewing system. What are the advantages? Describe the two modes in which SPOT's HRV capture data. What are the advantages of the repeat capability of the SPOT satellite system?
What is the difference in ground resolution between Landsat MSS, Landsat TM, SPOT multispectral mode and SPOT panchromatic mode? Describe the difference in scanning between the Landsat satellites and SPOT satellites.
What is a sun-synchronous orbit and why is it important for land resource mapping? What is a geostationary orbit and when is this type of orbit used?
What causes radar shadow? What is radar layover? What is radar foreshortening? What is polarization and how is it important in remote sensing? What are the causes of depolarization? Why is look direction important in radar remote sensing?
Describe the basic principles of synthetic aperture radar.
A lidar system has been defined as consisting of 4 components. What are they and for what purpose is each employed within a lidar system?
What is the difference between a low frequency and high frequency convolution filter? What is the purpose of the edge enhancement filter?
What is skew distortion? How do we deskew an image?
In our discussion on resampling, three different schemes were presented. Identify and describe the difference between two of them.
Bit errors are a random noise problem in digital data. Describe how one corrects for these errors. Use a sketch along with your written response.
What is the advantage or purpose of spectral ratioing?
Explain how the histogram is used in destriping.
Given the following band reflectance values: 180, 215, 205, 200, 235, 205, 195, 185, 206, compute the: a) mode; b) median; c) arithmetic mean; d) range; e) standard deviation
What is a color lookup table?
What is the value of the color lookup table to the image analyst?
Identify and describe two of the advantages of multispectral scanner data over photography.
What is a sampling error?
What does a histogram of remotely sensed data showing data compression to the lower 1/4 of the range suggest? Explain your answer.
Give an example of line drop-out. How is it corrected?
What is striping or banding and when does it occur? Describe one method of destriping.
A correlation coefficient between Band 1 and Band 2 of a hypothetical remotely sensed data is 0.95. What does this suggest to the image analyst.
Discuss three of the considerations that should be raised when looking at the radiometric correction of topographically induced effects.
Creating color composites by using the red, green and blue (RGB) display memory planes is useful to the analyst because they can view the different band combinations. How does the analyst pick which band combination to use when Landsat TM has six bands?
Atmospheric correction attempts to minimize or remove the contribution of path radiance. What is the consistency of path radiance?
One of the radiometric corrections is the sun elevation correction. Why is it employed and how is it determined?
Identify three design criteria used in the development of the USGS land use/land cover classification system.
Describe the specifications used in compiling the current use inventory within the Michigan Resource Inventory Program
Describe the results of tangential scale distortion.
What are mixed pixels?
What is the difference between spectral pattern recognition and spatial pattern recognition methods of classification? Describe the difference between spectral classes and informational classes.
Describe the difference between supervised and unsupervised classification. Describe the disadvantages/limitations of unsupervised classification. Describe unsupervised classification using the chain method. Describe the 3 basic steps in a typical supervised classification.
Describe the parallelepiped classifier. What is the main difficulty encountered with the parallelepiped classifier? What is the cause? Describe the concept of a minimum-distance-to-mean classifier and give an example.
Given an error matrix, determine the overall accuracy, producer's accuracy, user's accuracy, and the kappa coefficient.
Give an example of how haze compensation can be performed on MSS data.
Given a kernel and original DN values, compute a convoluted image DN value.
Given DNs from four channels of AVHRR data, compute the simple vegetation index (VI) and normalized difference vegetation index (NDVI).
A data set had the following DN statistics: Mean = 78, Minimum = 37, Maximum = 137. If the data output categories are 8 bits (0-255), what are the DN values (in integers) of some given data after performing a linear stretch?

This page is maintained by Bob Burtch and was last updated on 1 November 2006.
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