GIS Remote Sensing and Imagery 4

Question 1

What is 'pan-sharpening' in remote sensing image processing?

Accepted Answer

Merging a high-resolution panchromatic band with lower-resolution multispectral bands to create a high-resolution color image

Answer

Pan-sharpening fuses the spatial detail of a high-resolution panchromatic band with the color information of coarser multispectral bands to produce a higher-resolution color composite.

Question 2

In remote sensing, what does the 'bidirectional reflectance distribution function' (BRDF) describe?

Accepted Answer

How a surface reflects light differently depending on view and illumination angles

Answer

BRDF characterizes how a surface reflects incoming radiation as a function of both the illumination direction and the viewing direction.

Question 3

Which satellite sensor family is specifically designed for global forest change detection and widely used in Hansen's Global Forest Change dataset?

Accepted Answer

Landsat series

Answer

Hansen's Global Forest Change dataset uses Landsat imagery due to its decades-long archive, 30m resolution, and free global availability.

Question 4

What distinguishes 'active' from 'passive' remote sensing systems?

Accepted Answer

Active systems emit their own energy; passive systems detect naturally occurring energy

Answer

Active remote sensing systems (like radar and LiDAR) emit their own energy and record the return signal, while passive systems record energy from natural sources like the sun.

Question 5

What is the primary use of the shortwave infrared (SWIR) bands in multispectral remote sensing?

Accepted Answer

Discriminating between soil moisture, rock types, and cloud vs. snow

Answer

SWIR bands (1.3–2.5 µm) are sensitive to mineral composition, soil moisture, and can distinguish snow (absorbs SWIR) from clouds (reflects SWIR).

GIS - Geographic Information System Practice Test

GIS - Geographic Information System Practice Test

GIS Remote Sensing and Imagery 4