Instructions for use
LOWTRAN 7 can be roughly divided into three major parts:
(1) Atmospheric model input. Including vertical profiles of atmospheric temperature, air pressure, density, vertical profiles of the mixing ratio of water vapor, ozone, methane, carbon monoxide and nitrous oxide and vertical profiles of 13 other trace gases, profiles and radiation parameters of urban and rural atmospheric aerosols, fog, dust, volcanic ash, clouds and rain, such as extinction coefficients, absorption coefficients, spectral distribution of asymmetric factors and extraterrestrial solar spectrum.
(2) Detect geometric path, atmospheric refraction and absorbed gas content.
(3) Spectral transmittance calculation and atmospheric solar background radiation calculation (including or excluding multiple scattering).
LOWTRAN7 has five main input cards.
The atmospheric model is represented by the variable "MODEL". "MODEL" Select one of the six atmospheric models for different geographical locations, or indicate that user-defined meteorological data will be entered.
The boundary layer aerosol type is represented by the variable "IHAZE". IHAZE selects the extinction and meteorological visual range types in the boundary layer aerosol (0-2 km altitude) model. The dependence of the aerosol extinction coefficient on relative humidity is determined by the model atmospheric water vapor content determined by "MODEL".
Tropospheric/Stratospheric Profiles
Represented by the variable "ISEASN". "ISEASN" selects the seasonal characteristics of the tropospheric (2-10 km) and stratosphere (10-30 km) aerosol profiles. When using the 2-10 km profile, only the tropospheric aerosol extinction coefficient profile is used.
ground altitude
Represented by the variable "GNDALT", it gives the altitude of the ground (km), which is used to modify the aerosol profile below 6 km.
The initial height is represented by the variable "H1", and the unit is (km).
When IEMSCT=1 or =2, H1 must define the position of the observer or sensor. At this time, H1 and H2
Not interchangeable as in the transmittance calculation method.
Useful
Useful
Useful