Benha University
Faculty of Engineering _Shoubra
Surveying Engineering Department
Fourth Year
Year: 2016/2017
Semester: One
Remote Sensing and Photo
Interpretation
Quizzes
Lab Questions:
Choose the correct answer:
1. Remote Sensing is
a. Always done close up.
b. Deployed from a plane or satellite.
c. Deployed from a computer.
d. Deployed from a camera and video camera.
2. The First type of remote sensing were
a. Aerial photos.
b. Paintings from an air balloon.
c. TV remote controls.
d. Sketches from a French Map Maker
3. The visible portion the electromagnetic spectrum includes what colors?
a. Red, white, and blue.
b. Red, yellow, green, blue.
c. Infrared, ultraviolet, blue.
d. Green, purple, maroon, infrared
4. Which of the following waves is not part of the electromagnetic spectrum?
a. Microwaves.
b. Ultraviolet light.
c. Radio waves.
d. Ocean waves.
5. Why is water blue?
a. Because the atmosphere absorbs light corresponding to green and red wavelengths.
b. Because blue light has smaller wavelengths than red and green light.
c. Because the energy emitted from the sun is more concentrated in the blue wavelength
regions.
d. Because water absorbs longer wavelengths more than shorter wavelengths.
e. Because water absorbs shorter wavelengths more than longer wavelengths.
6. Which of the following effect do NOT result in geometrical errors/distortion in satellite images?
a. Earth curvature.
b. Earth rotation.
c. Atmospheric absorption.
d. Sensor platform motion.
e. Local topography.
7. Which one of the following statements is correct?
a. Snow albedo falls at all wave length with the increase of grain size.
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b. The effect of grain size on reflection is maximum in the near-IR region.
c. The effect of grain size on reflection is low in the visible region of the spectrum.
d. All of these.
8. Which one of the following frequency regions is a part of sun's radiation?
a. Ultraviolet frequency region.
b. Visible frequency region.
c. Infrared frequency region.
d. Radio frequency region.
e. All of these.
9. The instruments which provide electromagnetic radiation of specified wave length or a band of
wave lengths to illuminate the earth surface, are called:
a. Sensors.
b. Passive sensors.
c. Active sensors.
d. None of these.
10. The part radiation due to scattered/diffused radiation entering the field of view of a remote
sensor other than that from the required target,
a. Reduces the contrast of the image and also its sharpness.
b. Increases the contrast of the image but reduces the sharpness.
c. Increases both the contrast and sharpness.
d. Reduces the contrast but increases the sharpness.
11. Which one of the following errors is produced by platform characteristics of the sensor?
a. Altitude variation.
b. Altitude.
c. Orbit drift.
d. All of these.
12. The basic requirement of any sensor system, is :
a. Radiometric resolution.
b. Spatial resolution.
c. Spectral resolution.
d. Temporal resolution.
e. All of these.
13. The spectral region of the electromagnetic radiation which passes through the atmosphere
without much attenuation is known as:
a. Ozone hole.
b. Atmospheric window.
c. Ozone window.
d. Black hole.
14. Which one of the following statements is correct?
a. During the day, earth reflects solar radiation.
b. During the day earth reflects both solar radiation the emission from its surface.
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c. During the night, earth emits radiation from its surface.
d. All of these.
15. The remote sensing techniques applied for the earth's surface features, is generally confined to
the following wave lengths:
a. 0.4 to 1.3, 1.5 to 1.8, 2.2 to 2.6 μm.
b. 2.2 to 2.6, 3.0 to 3.6, 4.2 to 5.0 μm.
c. 4.2 to 5.0, 7.0 to 15.0 μm and 1 cm to 30 cm.
d. All of these.
16. The value of energy quantum for radiation of any frequency is proportional to:
a. The frequency.
b. The reciprocal of the energy.
c. The square of the frequency.
d. The square root of the frequency.
17. Remote sensing techniques makes use of the properties of-----emitted, reflected or diffracted by
the sensed objects:
a. Electric waves.
b. Sound waves.
c. Electromagnetic waves.
d. Wind waves.
18. Which one of the following relationship between the wave length (λ), and frequency and the
speed (C) of the electromagnetic wave is correct?
a. C = V + λ
b. C = 𝜆⁄𝑉
c. C = V*λ
d. C = 1⁄𝑉𝜆
19. The reflection of solar energy is characterized by the water content in the leaf, in the reflective
optical infrared:
a. Visible (0.4 - 0.7 μm) region.
b. Near-IR (0.7 - 1.3 μm) region.
c. Short wave-IR (1.3 - 2.7 μm) region.
d. None of these.
20. The interaction of the electromagnetic radiation produced with a specific wave length to
illuminate a target on the terrain for studying its scattered radiance, is called:
a. Passive remote sensing.
b. Active remote sensing.
c. Neutral remote sensing.
d. None of these.
21. A passive sensor uses:
a. Sun as the source of energy.
b. Flash light as a source of energy.
c. Its own source of energy.
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d. None of these.
22. The infrared portion of EMR lies between
a. 0.4 - 0.7 μm.
b. 0.5 mm to lm.
c. 0.7 - 1.3 μm.
d. 0.7 to 14 μm.
23. Depending upon the nature of the targeted object and the wave length of the electromagnetic
radiation incident on it, the radiation gets:
a. Reflected.
b. Absorbed.
c. Re-radiated.
d. Transmitted through.
e. All of these.
(True, False).
1. The more details represented in the DEM used in the Ortho-rectification procedures the higher
accuracy of the generated orthophoto.
2. A scanned map needs at least second order polynomial rectification before using.
3. Using 1m cell size DEM with a 2.5m pixel size digital image will generate a higher accuracy
orthophoto than using 2.5m cell size DEM.
4. Resampling is the process of assigning projection system to the digital image.
5. Jpeg images retains a higher degree of image quality than .tiff images.
6. A higher degree of polynomial requires more number of GCPs to be solved.
7. The 2nd order polynomial rectification requires at least 3 GCPs to be performed.
8. The Ortho-rectification process is performed mainly to correct for the perspective projection of
image.
9. First order polynomial rectification is equivalent to 2-D similarity transformation.
10. When using polynomial rectification the accuracy of the generated image depends only on the
number of GCPs used whatever the distribution of these points in the entire image.
11. Re-projection is the process of transforming the digital image from certain coordinate system to
another.
12. The color depth of the digital image is the number of bits used to represent the color for each
pixel.
13. With higher color depth, you get more visually appealing features but more memory is required.
14. Pixel digital number represents the intensity value of the measured solar radiance coming from an
area covered by this pixel.
15. The temporal resolution specifies the revisiting frequency of a satellite sensor for a specific
location.
16. A high spatial resolution is associated with a low spectral resolution and vice versa.
17. The spatial resolution specifies the pixel size of satellite images covering the earth surface.
18. A sensor's spectral resolution is the range of wavelengths that an imaging system can detect.
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19. Spatial Resolution of the Sensors: refers to the size of the smallest possible feature that can be
detected.
20. Spatial resolution refers to the smallest size that can be sampled in one pixel.
21. Resampling is the process of converting the analog signal to a digital number.
22. In the rectification process the accuracy of the generated image depends only on the number of
GCPs used whatever the distribution of these points in the entire image.
23. The Ortho-rectification process is performed mainly to correct for the perspective projection of
image.
24. Pixel digital number represents the intensity value of the measured solar radiance coming from an
area covered by this pixel.
25. Images where only large features are visible are said to have fine or high spatial resolution.
26. Deleting the projection info. of a satellite image will revert it to pixel coordinate system.
27. To make measurements on a scanned map, it needs to be resampled.
28. Resampling is the process of converting the analog signal to a digital number.
29. The advantages of bilinear interpolation include simplicity and the ability to preserve original
values in the unaltered scene.
30. Nearest Neighbor resampling method assigns the digital number (DN) of the closest input pixel (in
terms of coordinate location) to the corresponding output pixel.
31. Cubic convolution is a method used to determine the gray levels in an image through a weighted
average of the 16 closest pixels to the input coordinates.
32. At least 6 GCPs are necessary when doing a 1st order polynomial transformation.
33. Rigorous transformation directly uses the original mathematical formula of projections for reprojection without approximation.
34. Rigorous transformation for re-projection is a slow process, but the process has true geometric
fidelity.
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