Remote Sensing Flashcards
Remote sensing
Science of obtaining information about objects or areas from a distance, typically from aircraft or satellites
Remote sensing is an important part of identifying and measuring what?
The extent and rate of land cover change
Location of land cover change
Can be examined at a range of scales, from local, regional to global
Type
Category of land cover change occurring
Processes like deforestation or expansion of agriculture are examples of the type of land cover change often studied and exa,mned by geographers.
Rate
Speed at which changes have taken place (i.e. how much is being lost or altered each year or decade)
Extent
Size and area of land cover change occurring (i.e. in km squared or % or porportion of land altered)
Comparison of 2 sources provides what?
Effective identification of changes to land cover
OR
a remote sensing image may display the changes evident through colour.
Remote sensing techniques
True colour, infrared, elevation image
What does true colour do?
Displays earth’s colours in a way that allows changes to be easily identified.
Displays combination of 3 colour bands sensitive to red, green and blue visible light.
Provides clear display of changes to land cover
Most helpful in shwoing change to vegetation, oceans, agal blooms and spread of deserts.
Limitations of true colour
Changes at night are not available
Satellites can struggle differentiating between snow and clouds (both appear as bright white)
What does infrared do?
Detect differences in surface temperatures
What does infrared do?
Detect differences in surface temperatures
LIDAR (stands for what and is what?)
Light Detection & Ranging
Used to measure presence of chemicals in atmosphere and heights of objects on the surface
Radiometers measure what?
Infrared and ultraviolet radiation
Photometer measures what?
Optical properties of Earth’s surface
Can be used to measure the density and health of vegetation cover.
