Community Radiative Transfer Model
Encyclopedia
Community Radiative Transfer Model (CRTM) is the fast radiative transfer
model for calculations of radiances for satellite infrared or microwave nadir scanning radiometers (see push broom scanner
).
Given an atmospheric profile of temperature, variable gas concentrations, cloud and surface properties CRTM calculates radiances
and brightness temperature
s. The only mandatory input is water vapor
and ozone
. The range of temperatures and water vapour concentrations over which the optical depth computations are valid depends on the training datasets which were used.
CRTM contains forward, tangent linear, adjoint and K (full Jacobian matrices) versions of the model; the latter three modules for variational
assimilation or retrieval applications.
One of several applications of CRTM are retrievals of brightness temperature and sea surface temperature
from Advanced Very High Resolution Radiometer
sensor.
Atmospheric radiative transfer codes
An Atmospheric radiative transfer model, code or simulator calculates radiative transfer of electromagnetic radiation through a planetary atmosphere, such as the Earth's.- Methods :...
model for calculations of radiances for satellite infrared or microwave nadir scanning radiometers (see push broom scanner
Push broom scanner
A Push broom scanner is a technology for obtaining satellite images with optical cameras. It is used for passive remote sensing from space. In a push broom sensor, a line of sensors arranged perpendicular to the flight direction of the spacecraft is used. Different areas of the surface are imaged...
).
Given an atmospheric profile of temperature, variable gas concentrations, cloud and surface properties CRTM calculates radiances
Radiance
Radiance and spectral radiance are radiometric measures that describe the amount of radiation such as light or radiant heat that passes through or is emitted from a particular area, and falls within a given solid angle in a specified direction. They are used to characterize both emission from...
and brightness temperature
Brightness temperature
Brightness temperature is the temperature a black body in thermal equilibrium with its surroundings would have to be to duplicate the observed intensity of a grey body object at a frequency \nu....
s. The only mandatory input is water vapor
Water vapor
Water vapor or water vapour , also aqueous vapor, is the gas phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Under typical atmospheric conditions, water vapor is continuously...
and ozone
Ozone
Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...
. The range of temperatures and water vapour concentrations over which the optical depth computations are valid depends on the training datasets which were used.
CRTM contains forward, tangent linear, adjoint and K (full Jacobian matrices) versions of the model; the latter three modules for variational
assimilation or retrieval applications.
One of several applications of CRTM are retrievals of brightness temperature and sea surface temperature
Sea surface temperature
Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...
from Advanced Very High Resolution Radiometer
Advanced Very High Resolution Radiometer
The Advanced Very High Resolution Radiometer is a space-borne sensor embarked on the National Oceanic and Atmospheric Administration family of polar orbiting platforms . AVHRR instruments measure the reflectance of the Earth in 5 relatively wide spectral bands...
sensor.
See also
- List of atmospheric radiative transfer codes
- RTTOV (radiative transfer code)RTTOV (radiative transfer code)RTTOV - the fast radiative transfer model for calculations of radiances for satellite infrared or microwave nadir scanning radiometers ....
External links
- http://www.star.nesdis.noaa.gov/smcd/spb/CRTM/
- MICROS, Monitoring of IR Clear-sky Radiances over Oceans for SST