EVSP322 Remote Sensing & GIS EVSP322 – Assessment 2
(20 points, 10 points/each) Part 1 – True/False and Why – Identify whether the statement is
true or false. Then, in a well-developed paragraph explain why you selected that answer. If the
answer is true, consider defining key terms to justify your response. If the answer is false,
identify the corrected statement and explain. Answer both questions.
1 – A serious practical problem with unsupervised image classification is that clear matches
between spectral and informational classes are not always possible. That is, some informational
categories may not have direct spectral counterparts, and vice versa.
2 – Considering sources of classification error, the character of the landscape contributes to the
potential for error through the complex patterns of parcels that form the scene. A very simple
landscape composed of large, uniform, distinct categories is more difficult to classify accurately
than one with small, heterogeneous, indistinct parcels arranged in a complex pattern.
(30 points, 5 points/each) Part 2 – Multiple Choice – Select the *best* response for each
question.
3 – Digital image classification is the process of assigning pixels to classes. Which of the
following statements is *not* true regarding digital image classification?
A. The classes form regions on a map or image, so that after classification the digital
image is presented as a mosaic of uniform parcels, each identified by a color or
symbol.
B. Pixels within classes are spectrally more similar to one another than they are to pixels
in other classes.
C. The classes are heterogeneous, presenting a divergent variety of pixel details.
D. The classification itself may be the object of the analysis (e.g. classification of land
use).
E. None of the above.
4 – This term describes the visible features of the Earth’s surface (e.g. vegetative cover,
transportation and communication structures), also described as the physical features that occupy
the surface of the Earth (e.g. water, forest, urban structure).
A. land cover B. impervious surface
C. land use D. nominal cover
E. none of the above
5 – Which of the following is an essential component that must be included in a GIS?
A. data
B. computer programs
C. personnel to operate and maintain the GIS
D. computer hardware
E. all of the above are elements that must be included in a GIS
6 – Unsupervised classification can be defined as the identification of natural groups, or
structures, within multispectral data. Which of the following is considered a disadvantage or
limitation to unsupervised classification?
A. Extensive prior knowledge of the region is required.
B. The analyst has limited control over the menu of classes and their specific identities.
C. Unique classes are recognized as distinct units.
D. Opportunity for human error is maximized.
E. All of the above.
7 – Which of the following statements is incorrect regarding analysis of land-use and land-cover
change using visual interpretation?
A. Two basic conditions must be satisfied before change data can be compiled using and
two maps or images: informational compatibility and geometric compatibility.
B. The two maps must use the same classification system, or at least two classification
systems that are compatible.
C. The two maps must be compatible with respect to scale and geometry.
D. The two maps must be compatible with respect to level of detail.
E. All of the above are correct statements.
8 – Which of the following is a true statement regarding a GIS?
A. A GIS must be supported by the ability to perform certain operations related to the
geographic character of the data.
B. Software for a GIS must be able to perform operations that relate values at one
location to those at neighboring locations.
C. A GIS requires specialized programs tailored for the manipulation of geographic data.
D. Data for a GIS is not based upon a single set of information.
E. All of the above are true statements regarding a GIS.
(20 points, 4 points/each) Part 3 – Fill in the Blank – Complete the following blanks. Answer
all questions in Part 3. Please check your spelling!
9 – Databases primarily maintained by governmental agencies and other organizations, ____
____ assemble spectra that have been acquired as test sites representative of various terrain and
climate zones, observed in the field under natural conditions.
10 – In the context of image classification, a ____ ____ procedure requires considerable
interaction with the analyst, who must guide the classification by identifying areas on the image
that are known to belong to each category. It can be defined informally as the process of using
samples of known identity to classify pixels of known identity.
11 – Considering the spacing of observations and their relevance to field data in remote sensing,
____ ____ describes the tendency of measurements at one location to resemble those at nearby
locations.
12 – ______ _______ denotes the ability of a sensor to define fine wavelength intervals.
13 – In image preprocessing, ____ refers to the application of algorithms to adjust incorrect
brightness values to values thought to be near the correct values.
(30 points, 15 points/each) Part 4 – Essay – Provide detailed essay responses for each question
below. Responses should show your mastery of the subject.
14 – Describe the concept of local differential GPS and its significance to understanding error.
15 – Compare and contrast the two basic data structures of GIS, discussing advantages and
disadvantages of each.