Thermal Remote Sensing Flashcards
Sources of shortwave Radiation
The sun
Reflections of EMR off the Earth
Sources of Longwave Radiation
Emission off the Earth
Relationship between longwave and shortwave
Blackbody Radiation Curves
Higher temp = shorter wavelength
Thermal Radiation definiton
Heat
Kinetic energy within an object due to random motion of particles then converted to EMR
Generally long wave
Temperature definiton
The measure of the average kinetic energy of particles in a substance
higher temp = higher velocity
Thermal specrum
3 - 14 um
Lowest temp on record
-89.2 c in Antartica
Highest temp on record
56.7 c in Death Valley CA
Why do TIR bands have lower spatial res than visible bands
Q = (hc)/v
Longer wavelengths have lower energy, they dont travel as far
TIR sensors have bigger IFOV to reliable catch enough energy
Air temp vs Surface temp in RS
RS measures surface temperature while weather stations measure air temp
Finding Temp with RS
Convert DNs to Top of Atmos (TOA) radiance
Convert TOA radiance to brightness temperature
Calculate emissivity
Calculate Land Surface Temperature (LST)
Emissivity definition
A surface materials effectiveness in emitting energy as thermal radiation
measured 0 to 1
Opposite Albedo
Types of Urban Heat Island effects
Surface Layer UHI
Canopy Layer
Surface
Boundary
Blackbody emissivity and problem
e=1
This is a theoretical entity, nothing we know of absorbs all EMR (except maybe the sun)
Graybodies
real objects that radiate less thermal energy than a blackbody
Urbanization definiton
population increase in proportion of people living in urban areas
Land Use Land Cover Change (LULCC)
general term for the human modification of the Earth’s surface
Impacts of Urbanization on Urban Climate
Increased air and surface temp
Increased surface run off
Decreased biodiversity
Downgraded air quality
Urban Heat Island Effect definiton
Urban areas have higher temperature in comparison to surrounding rural areas
Consequences of UHI effect
Increased energy and water consumption
Compromised human health and comfort
Downgraded air quality
Increased duration and magnitude of heat waves
Boundary Layer UHI
Lowest part of the atmos
100 - 2000m above surface
Measured by weather baloons
Surface layer UHI
Highest altitude of all the buildings and structures within a city
Measured by rooftop station or eddy-covariance flux tower
Canopy layer UHI
Layer of air beneath the mean height of the buildings and trees
measured by weather stations 2m above ground
Surface UHI
Remotely Sensed
Land Surface Temperature (LST)
