Remote Sensing – MCQs

1. Remote sensing primarily refers to:
(A) Collecting data from satellites or aircraft without direct contact
(B) Studying rocks by hand sample
(C) Measuring soil moisture directly in the field
(D) Laboratory-based chemical analysis

2. The main source of energy for optical remote sensing is:
(A) Sunlight
(B) Moonlight
(C) Radar signals
(D) Artificial lamps

3. The Landsat series satellites are mainly used for:
(A) Weather forecasting
(B) Resource and land use monitoring
(C) Communication
(D) Astronomy

4. The first Earth Resources Technology Satellite (ERTS-1) was later renamed:
(A) SPOT
(B) IRS
(C) Landsat-1
(D) Meteosat

5. The wavelength range of visible light used in remote sensing is approximately:
(A) 0.4 – 0.7 µm
(B) 1 – 3 µm
(C) 3 – 5 µm
(D) 8 – 14 µm

6. Thermal infrared remote sensing is sensitive to:
(A) Reflected solar radiation
(B) Emitted radiation from the Earth’s surface
(C) Gamma rays
(D) UV absorption

7. Which of the following sensors is an active sensor?
(A) MSS
(B) TM
(C) LIDAR
(D) AVHRR

8. The microwave region is especially useful in remote sensing because:
(A) It is unaffected by clouds and atmosphere
(B) It provides high-resolution optical images
(C) It covers only the visible spectrum
(D) It is absorbed strongly by the atmosphere

9. Which remote sensing satellite is operated by ISRO?
(A) IRS series
(B) SPOT
(C) Landsat
(D) Ikonos

10. The French satellite system for Earth observation is called:
(A) SPOT
(B) Meteosat
(C) IRS
(D) ERS

11. The spectral resolution of a sensor refers to:
(A) Number of pixels per unit area
(B) Ability to distinguish between different wavelengths
(C) Time taken to revisit the same area
(D) Area covered on the ground

12. The spatial resolution of Landsat TM is:
(A) 80 m
(B) 30 m
(C) 15 m
(D) 250 m

13. The swath of a remote sensing satellite refers to:
(A) The revisit time
(B) The width of the ground area covered in one pass
(C) The altitude of the satellite
(D) The spectral range of the sensor

14. Which type of remote sensing uses its own energy source?
(A) Passive
(B) Active
(C) Optical
(D) Thermal

15. NDVI (Normalized Difference Vegetation Index) is calculated using:
(A) Red and Blue bands
(B) Red and Near-infrared bands
(C) Green and Blue bands
(D) Thermal and Microwave bands

16. Which of the following is a radar imaging satellite?
(A) IRS-1A
(B) RADARSAT
(C) Landsat-7
(D) SPOT-2

17. Hyperspectral sensors are characterized by:
(A) A few broad spectral bands
(B) Hundreds of narrow spectral bands
(C) Only thermal bands
(D) Only microwave bands

18. The Indian satellite Cartosat is mainly used for:
(A) Communication
(B) High-resolution mapping and cartography
(C) Astronomy
(D) Weather observation

19. The geostationary orbit is located at approximately:
(A) 360 km
(B) 1000 km
(C) 36,000 km
(D) 100,000 km

20. Which platform is typically used for aerial remote sensing?
(A) Aircraft
(B) Satellite
(C) Space Shuttle
(D) Rover

21. AVHRR sensor is carried by:
(A) NOAA satellites
(B) Landsat satellites
(C) IRS satellites
(D) Meteosat satellites

22. Microwave remote sensing is widely applied for:
(A) Mineral identification
(B) Soil moisture estimation
(C) Atmospheric ozone study
(D) Ocean color mapping

23. The revisit time of Landsat satellites is:
(A) 8 days
(B) 16 days
(C) 24 days
(D) 32 days

24. Panchromatic sensors record data in:
(A) Multiple narrow bands
(B) A single broad band covering visible spectrum
(C) Only thermal bands
(D) Only microwave region

25. Which of the following satellites is mainly used for weather monitoring?
(A) Meteosat
(B) Cartosat
(C) SPOT
(D) IRS

26. Which principle is remote sensing mainly based on?
(A) Reflection, absorption, and emission of electromagnetic radiation
(B) Nuclear magnetic resonance
(C) Gravitational force measurement
(D) Mechanical vibration

27. The term “sun-synchronous orbit” means:
(A) Satellite follows the Sun’s rotation
(B) Satellite passes over the same part of Earth at the same local solar time
(C) Satellite orbits the Sun directly
(D) Satellite stays fixed above one point on Earth

28. MODIS sensor provides data at spatial resolutions of:
(A) 1 m, 2 m
(B) 30 m, 80 m
(C) 250 m, 500 m, 1000 m
(D) 10 km, 50 km

29. Which agency operates the GOES satellites?
(A) NASA
(B) NOAA
(C) ISRO
(D) ESA

30. A digital image in remote sensing consists of:
(A) Rows and columns of pixels
(B) Physical photographs
(C) Scanned topographic maps
(D) Radar echoes only

31. In remote sensing, the ground resolution cell corresponds to:
(A) A single pixel
(B) A spectral band
(C) A swath
(D) An orbit

32. LIDAR is especially used for:
(A) Measuring chlorophyll content
(B) Generating Digital Elevation Models (DEMs)
(C) Recording thermal emission
(D) Detecting soil moisture

33. Which color in a false-color composite (FCC) usually indicates healthy vegetation?
(A) Blue
(B) Green
(C) Red
(D) Black

34. Which of the following is NOT an application of remote sensing?
(A) Mineral exploration
(B) Land cover mapping
(C) Soil moisture analysis
(D) Manual rock sampling in the field

35. Which sensor onboard Landsat provides higher-resolution panchromatic images?
(A) MSS
(B) TM
(C) ETM+
(D) AVHRR

36. Which organization launched the Copernicus Sentinel satellites?
(A) ISRO
(B) NASA
(C) ESA
(D) NOAA

37. The principle of synthetic aperture radar (SAR) is based on:
(A) Thermal emission
(B) Microwaves and Doppler shift
(C) Ultraviolet absorption
(D) Visible reflectance

38. Which type of resolution refers to the ability to distinguish objects that are close together in time?
(A) Spectral
(B) Spatial
(C) Temporal
(D) Radiometric

39. Radiometric resolution refers to:
(A) Ability to measure slight differences in energy
(B) Width of swath
(C) Number of spectral bands
(D) Duration of revisit

40. Which of the following has the finest spatial resolution?
(A) MODIS
(B) AVHRR
(C) IKONOS
(D) Meteosat

41. The concept of “false-color composite” is used to:
(A) Display non-visible spectral bands in visible colors
(B) Improve atmospheric correction
(C) Compress image data
(D) Increase pixel size

42. Which of the following is used in geological remote sensing to detect mineral composition?
(A) Hyperspectral sensors
(B) Panchromatic sensors
(C) Microwave sensors
(D) Thermal scanners

43. Which orbit is most suitable for weather satellites?
(A) Sun-synchronous
(B) Polar orbit
(C) Geostationary orbit
(D) Molniya orbit

44. Which sensor is most suitable for ocean color studies?
(A) ETM+
(B) MODIS
(C) LIDAR
(D) SAR

45. GPS is an example of:
(A) Remote sensing system
(B) Ground-based navigation system
(C) Active radar system
(D) Astronomical telescope

46. The main advantage of microwave remote sensing is:
(A) It cannot penetrate clouds
(B) It works day and night in all weather
(C) It requires sunlight
(D) It only works over land

47. Which of the following satellites is primarily used for disaster monitoring?
(A) IRS-P6 (Resourcesat)
(B) NOAA-AVHRR
(C) Sentinel-1
(D) All of the above

48. The principle of photogrammetry is mainly used in:
(A) Topographic mapping from aerial photographs
(B) Weather prediction
(C) Soil classification
(D) Ocean color monitoring

49. The Global Positioning System (GPS) uses how many satellites for full coverage?
(A) 12
(B) 18
(C) 24
(D) 36

50. Remote sensing data combined with GIS is widely used for:
(A) Urban planning and resource management
(B) Laboratory testing
(C) Manual soil sampling
(D) Fossil collection