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Civil Engineering :: Elements of Remote Sensing

  1. The ratio of the total solar radiant energy returned by a planetary body to the total radiant energy incident on the body, the called:

  2. A.

     Reflectance

    B.

     Reflectance factor

    C.

     Albedo

    D.

     None of these

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  3. Which one of the following parameters is accurate for DGPS?

  4. A.

     Positional accuracies ~ 1 - 2 m if rover is less than 1-2 km from the reference station

    B.

     Positional accuracies ~ 2 - 5 m if rover is less than 2-5 km from the reference station

    C.

     Positional accuracies ~ 5 - 10 m if rover is less than 5-10 km from reference station

    D.

     Positional accuracies ~ 5 - 10 m if rover is less than 25 km

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  5. Which one of the following errors is produced by platform characteristics of the sensor?

  6. A.

     Altitude variation

    B.

     Altitude

    C.

     Orbit drift

    D.

     All of these

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  7. If electric permittivity and magnetic permeability of the medium are respectively ‘ε’ and ‘μ’, then the velocity (Cm) of the electromagnetic wave in the medium is given by:

  8. A.

     Cm = 1/εμ

    B.

     Cm = 1/√8 μ

    C.

     Cm = 5/√εμ

    D.

     None of these

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  9. The altitudinal distance of a geostationary satellite from the earth is about:

  10. A.

     26,000 km

    B.

     30,000 km

    C.

     36,000 km

    D.

     44,000 km

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  11. Which one of the following statements is correct regarding the GPS satellites?

  12. A.

     The nominal altitude is about 20,200 km

    B.

     The inclination of axis satellite is 55°

    C.

     The satellite transmits two L band signals (L1 with 1575.42 MHz and L2 with 1276.6 MHz)

    D.

     All of these

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  13. For C band Synthetic Aperture Radar (SAR) with Doppler band width of 1300 Hz, the coherence length loch is:

  14. A.

     130 km

    B.

     230 km

    C.

     250 km

    D.

     500 km

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  15. Remote sensing techniques make use of the properties of ___________ emitted, reflected or diffracted by the sensed objects:

  16. A.

     Electric waves

    B.

     Sound waves

    C.

     Electromagnetic waves

    D.

     Wind waves

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  17. A perfectly black body:

  18. A.

     Is a diffuse emitter

    B.

     Absorbs all the radiations of every wave lengths

    C.

     Emits power of every wave length

    D.

     All the above

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  19. Which one of the following parameters is considered to determine the reflectance of a vegetation canopy?

  20. A.

     Solar zenith angle

    B.

     Azimuth angle

    C.

     Look angle

    D.

     All of these

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