Applications of GIS UPDATED Exam
Questions and CORRECT Answers
Reflectance - CORRECT ANSWER - ratio between incident and reflected energy
wavelengths to say which type of surface is there
Remote sensing - CORRECT ANSWER - Earth observation (EO), measuring properties of
objects with no direct contact, using some form of energy
Which spectrums used in GIS? - CORRECT ANSWER - microwaves, infrared and visible
EM spectrums
Green band - CORRECT ANSWER - water > blue
Red band - CORRECT ANSWER - soil with not as much vegetation cover > green
Near infrared (NIR) band - CORRECT ANSWER - vegetation > red
Spectral resolution - CORRECT ANSWER - used to correct/check atmosphere
Spatial resolution - CORRECT ANSWER - depends on viewing angle, distance from the
object (altitude), sampling scheme -- raster model
IFOV (Instantaneous Field of View) - CORRECT ANSWER - - measure of the spatial
resolution of a remote sensing imaging system.
- has the following attributes: Solid angle through which a detector is sensitive to radiation.
Radiometric resolution - CORRECT ANSWER - number of bits per pixel, ability of sensor
to distinguish incoming energy signals, quantization of the signal of energy into integer values
(digital numbers), amount of DN values = 2k
, Temporal resolution - CORRECT ANSWER - capacity of sensor and satellite to receive
data from earth at specific frequency for specific location (depends on orbital path, sensor
capability, missions planning)
Sun - CORRECT ANSWER - Source of EM energy, passive sensors
Optical (image) data - CORRECT ANSWER - record EM energy reflected by the Earth
surface in visible, near-infrared (+
short-wavelength infrared) part of the EM spectrum;
ground cell size depends on sensor viewing angle and distance from the Earth surface;
Landsat level 1 data - CORRECT ANSWER - includes basic radiometric corrections and
geometric corrections
Landsat level 2 data - CORRECT ANSWER - includes atmospheric corrections (image
data converted to reflectance)
Landsat level 3 data - CORRECT ANSWER - data are various products (e.g., snow cover,
burned area)
Best quality Landsat data - CORRECT ANSWER - collection 2, tier 1
Measuring Earth surface reflectance - CORRECT ANSWER - Need:
[1] to correct TOA radiance for various atmospheric effects, receiving
bottom-of atmosphere radiance (BOA)
[2] to calculate amount of incident solar energy [solar irradiance] at the
Earth surface (based on Sun position and distance, atmospheric effects and
topography)
Questions and CORRECT Answers
Reflectance - CORRECT ANSWER - ratio between incident and reflected energy
wavelengths to say which type of surface is there
Remote sensing - CORRECT ANSWER - Earth observation (EO), measuring properties of
objects with no direct contact, using some form of energy
Which spectrums used in GIS? - CORRECT ANSWER - microwaves, infrared and visible
EM spectrums
Green band - CORRECT ANSWER - water > blue
Red band - CORRECT ANSWER - soil with not as much vegetation cover > green
Near infrared (NIR) band - CORRECT ANSWER - vegetation > red
Spectral resolution - CORRECT ANSWER - used to correct/check atmosphere
Spatial resolution - CORRECT ANSWER - depends on viewing angle, distance from the
object (altitude), sampling scheme -- raster model
IFOV (Instantaneous Field of View) - CORRECT ANSWER - - measure of the spatial
resolution of a remote sensing imaging system.
- has the following attributes: Solid angle through which a detector is sensitive to radiation.
Radiometric resolution - CORRECT ANSWER - number of bits per pixel, ability of sensor
to distinguish incoming energy signals, quantization of the signal of energy into integer values
(digital numbers), amount of DN values = 2k
, Temporal resolution - CORRECT ANSWER - capacity of sensor and satellite to receive
data from earth at specific frequency for specific location (depends on orbital path, sensor
capability, missions planning)
Sun - CORRECT ANSWER - Source of EM energy, passive sensors
Optical (image) data - CORRECT ANSWER - record EM energy reflected by the Earth
surface in visible, near-infrared (+
short-wavelength infrared) part of the EM spectrum;
ground cell size depends on sensor viewing angle and distance from the Earth surface;
Landsat level 1 data - CORRECT ANSWER - includes basic radiometric corrections and
geometric corrections
Landsat level 2 data - CORRECT ANSWER - includes atmospheric corrections (image
data converted to reflectance)
Landsat level 3 data - CORRECT ANSWER - data are various products (e.g., snow cover,
burned area)
Best quality Landsat data - CORRECT ANSWER - collection 2, tier 1
Measuring Earth surface reflectance - CORRECT ANSWER - Need:
[1] to correct TOA radiance for various atmospheric effects, receiving
bottom-of atmosphere radiance (BOA)
[2] to calculate amount of incident solar energy [solar irradiance] at the
Earth surface (based on Sun position and distance, atmospheric effects and
topography)
