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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
- Mie scattering and absorption by two concentric spheres
- IDL interface for the T-Matrix fortran of Mishchenko and Travis
- Molecular scattering according to Rayleigh theory
- Blackbody radiance according to Planck's function
- 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 a mixture of two substances according to Debye
- 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 )
- Refractive index of H2SO4 vs. temperature and composition according to Neidziela et al. [1998]
- Refractive index of moist air (index_air.pro)
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
- Ice density for 93K < T < 273K
Aerosols and Particles
- Lognormal size distribution (lognorm.pro)
- Gaussian size distribution (gaussian_sdist.pro)
- Fall velocity of a sphere according to Stokes law (fall_speed.pro)
- Compute optical properties of clouds and aerosols
- Compute the change in saturation vapor pressure over an ice sphere, the Kelvin effect (vapor_over_ice_sphere.pro)
- Critical radius of ice particles according to Rapp & Thomas [2006] (critical_radius_ice.pro)
- Fall velocity of mesospheric ice particles according to Turco et al. [1982] (fall_speed_pmc.pro)
- PMC thermodynamic equilibrium (0D) model (pmc_0d_model2a.pro)
The Sun & Earth
- Solar intensity as a function of angular distance from sun center for a sun view from Earth ("Allen curve") (solim.pro)
- Solar image with refraction at the limb for a sun view from Earth orbit (solar_image_outline.pro)
- Solar intensity as a function of wavelength for 0.2 to 196 microns (program, data file)
- Earth - Sun distance for a particular date (soldis.pro)
- Local solar time (solar_time.pro)
- Solar zenith angle (sol_zen_ang.pro)
- Earth radius for a given geodetic latitude (earth_rad_geodetic.pro)
Date and Time
- Convert date as yyyymmdd to julian date (yyyymmdd_2_julian.pro)
- Convert day of year and year to a character date string (doy2date.pro)
- Compute elapsed time from January 1 in a reference year, for a given date and time (elapsed_time.pro)
- Convert YYYYDDD to month, date, year, and a character date (juldat.pro)
- Convert month, date, and year to YYYYDDD and character date (juldat2.pro)
- Convert UNIX time (cmsystime.pro)
- Convert UNIX time with nicer output (convert_unix_time.pro)
- Find the day of year for summer solstice (solstice.pro), a plot of the data and fit used in solstice.pro
- Compute days from solstice for a given date (yyyydoy_2_dfs.pro)
Geometry
- Great circle distance and heading between two locations (great_circle.pro)
- Relate angular field of view at the spacecraft to linear distance subtended at tangent for a limb view (ang2lin_fov.pro)
- Relate linear distance subtended at tangent for a limb view, to angular field of view at the spacecraft (lin2ang_fov.pro)
- Calculate path length of the tangent point sample volume for a limb view from space (tan_path_len.pro)
Math
- Two-point linear interpolation (interp_2pt.pro)
- Compute a histogram for your
data,
the median value (most frequent), and the mean and std. deviation (histo.pro)
- Find all interpolates on a multi-valued function (interp_all.pro)
- Generate a set of random numbers that has a mean value below a specified limit (get_random_nums.pro)
- Find the half power points for a curve (e.g., a FOV or RSR curve) (half_power.pro)
- Generate a uniform logarithmic series of numbers (range_logx.pro)
Meteorology
- Find the tropopause (find_trop.pro)
- Compute air density (airdensity.pro)
Working With Data Sets
- Find time-space coincidences between two data sets (coincidence.pro)
- Compute comparison statistics for sets of coincident profiles (compare_profiles_sub.pro)
- Generate a uniform time series (time_series_maker.pro)
- Generate an average profile (ave_pro_maker.pro)
- Generate a uniform time-height cross section (x_section_maker.pro)
- Apply a box-car smooth (box_car.pro)
- See what's inside a NCDF file (ncdf_cat.pro)
- Grid data in one dimension (grid_data_1d.pro)
- Grid data in two dimensions (e.g., lat vs. lon or time vs. height) (grid_data_2d.pro)
Plotting
- Draw a color bar (color_bar.pro)
- Use the HALOE color table: program, file ( right click "save as...")
- Make a latitude vs. longitude color contour map with an Earth projection underneath (plot_color_map_sub.pro)
- Define plot symbols as a circle or square (open or filled) (user_sym.pro)
AIM / SOFIE
- Extract SOFIE variables at Zmax (sofie_at_zmax.pro)
- SOFIE level 2 file reader (sofie_read_l2_netcdf.pro)
- SOFIE ncdf summary file reader (summary version "S2", sofie_read_summary_s2.pro)
- SOFIE ncdf summary file reader (summary version "S3", sofie_read_summary_s3.pro)
- Routine to read many SOFIE "S3" ncdf summary files (sofie_read_summary_s3_all.pro)