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Scientific Software in IDL
This page offers IDL routines addressing a variety of topics. If you have problems or wish to share a program contact Mark Hervig (m.e.hervig@gats-inc.com).
Radiation and Optics
Rayleigh scattering and absorption by spheres
Mie scattering and absorption by spheres
Molecular scattering according to Rayleigh theory
Blackbody radiance according to Planck's function
Refractive index of ice at 100 K temperature
Refractive index of ice at 163 K temperature
Refractive index of ice at 266 K temperature
Refractive index of nitric acid trihydrate (NAT) at 196 K temperature
Refractive index of nitric acid dihydrate (NAD) at 184 K temperature
Refractive index of liquid ternary HNO3-H2O-H2SO4 aerosols at wavelengths less than 2 microns
Refractive index of pure liquid water
Refractive index of H2SO4-H2O (sulfate) solution at 215 K temperature (
program
and
data file
)
Temperature dependence of the refractive index of a liquid according to Lorentz-Lorenz
Refractive index of a mixture of two substances according to Maxwell-Garnet
Refractive index of H2SO4 vs. temperature and composition
according to Neidziela et al. [1998]
Thermodynamics
Equilibrium properties of nitric acid trihydrate (NAT)
Equilibrium properties of nitric acid dihydrate (NAD)
Equilibrium properties of nitric acid pentahydrate (NAP)
Equilibrium properties of sulfuric acid tetrahydrate (SAT)
Equilibrium properties of liquid ternary HNO3-H2O-H2SO4 aerosols
Equilibrium properties of ice
Equilibrium properties of solid CO2
Saturation water vapor pressure over ice according to Goff-Gratch
Saturation water vapor pressure over ice according to Marti and Mauersberger
Saturation water vapor pressure over ice according to Mauersberger and Krankowsky
Saturation water vapor pressure over ice according to Rapp and Thomas [2005]
Saturation water vapor pressure over liquid water according to Goff-Gratch
Saturation water vapor pressure over liquid water according to Clegg and Brimblecombe
Density of liquid H2SO4-H2O, HNO3-H2O, or ternary HNO3-H2O-H2SO4 solutions
Equilibrium composition of sulfate aerosols (wt.% H2SO4), according to Steele and Hamill, 1981
Equilibrium composition of sulfate aerosols (wt.% H2SO4), according to Tabazadeh et al., 1997
Altitude change between two pressure levels using the hydrostatic equation
Column ozone amount in Dobson units
Aerosols and Particles
Functional description of a lognormal size distribution
Fall velocity of a sphere according to Stokes law
Compute optical properties of clouds and aerosols
Compute the change in saturation vapor pressure over an ice sphere
(the Kelvin effect)
Our Sun
Solar intensity as a function of angular distance from sun center for a sun view from Earth
("Allen curve")
Solar images with and without refraction at the limb path tangent point for a sun view from Earth orbit
Solar intensity as a function of wavelength for 0.2 to 196 microns (
program
,
data file
)
Calculate the Earth - Sun distance for a particular date
Calculate local solar time
Calculate solar zenith angle
Date and Time
Convert date as yyyymmdd to julian date
Convert day of year and year to a character date string
(e.g., inputing day 172 in year 1994 gives "21-Jun-1994")
Compute elap
sed time from January 1 in a reference year, for a given date and time
Geometry
Great circle distance and heading between two locations
Relate angular field of view at the spacecraft to linear distance subtended at tangent for a limb view
Relate linear distance subtended at tangent for a limb view, to angular field of view at the spacecraft
Calculate path length of the tangent point sample volume for a limb view from space
Math
Two-point linear interpolation
Compute a histogram for your data, the median value (most frequent), and the mean and std. deviation
Find all interpolates on a multi-valued function
(i.e., find all Y values for a given X on the curve X vs. Y)
Working With Data Sets
Find time-space coincidences between two data sets
Compute comparison statistics for sets of coincident profiles
Graphics
Draw a color bar
Check out
Coyote's Guide
to IDL programming for useful tips and routines.