21. The changes in the reflectivity/emissivity with time, is called ?
A. Spectral variation
B. Spatial variation
C. Temporal variation
D. None of these
✅ The correct answer is option C.
Elements of Remote Sensing MCQs
22. Who coined the term, ‘Remote sensing_______________?
A. Evelyn L. Pruitt, a geographer
B. Gaspard Felix Tournachon, a French scientist
C. Wilbur Wright, an Italian scientist
D. None of these
✅ The correct answer is option A.
23. Remote sensing techniques make 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
✅ The correct answer is option C.
24. Which one of the following parameters is accurate for DGPS ?
A. Positional accuracies ~ 1 – 2 m if rover is less than 1-2 km from the reference station
B. Positional accuracies ~ 2 – 5m if rover is less than 2-5 fm 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
✅ The correct answer is option A.
25. Which on speed C. of the electromagnetic wave is correct ?
A. C = v
B. C = /v
C. C = v
D. C = 1/
✅ The correct answer is option C.
26. The entire range of the electromagnetic spectrum spans a large spectrum of wave lengths varying from__________________?
A. 10-10 to 106 m
✅ The correct answer is option A.
27. sensor IFOV is proportional to_________________?
A. sin2
B. cos2
C. sec2
D. tan2
✅ The correct answer is option C.
28. For C band Synthetic Aperture Radar (SAR) with Doppler band width of 1300 Hz, the coherence length loch is_____________?
A. 130 km
B. 230 km
C. 250 km
D. 500 km
✅ The correct answer is option B.
29. The altitudinal distance of a geostationary satellite from the earth is about_________________?
A. 26,000 km
B. 30,000 km
C. 36,000 km
D. 44,000 km
✅ The correct answer is option C.
30. The coherence length over which there is a strong relationship between amplitudes is_________________?
A. Directly proportional to the bandwidth
B. Inversely proportional to the bandwidth
C. The square of the bandwidth
D. None of these
✅ The correct answer is option B.