## mie_size_dist.pro## PurposeThe ## Calling the procedure
The input parameters in the above call are: `distname`: Name of the size distribution. 'log_normal' or 'modified_gamma' according to Hansen and Travis 1974.`Nd`: Number density of particles in the distribution. This value must be a scalar quantity greater than zero.`params`: Array of size distribution parameters. For 'log_normal':`params[0]`Median radius of the particle distribution`params[1]`Spread of the distribution, such that the standard deviation of ln(r) is ln(S)
`params[0]`: a`params[1]`: b`params[2]`: Minimum radius in the distribution`params[3]`: Maximum radius in the distribution
`wavenumber`: Wavenumber of light. This must be a positive scalar and it's units should match those of`Rm`(i.e. if`Rm`is in microns,`wavenumber`should be in 1/microns).`Cm`: Complex refractive index. Only one refractive index value can be used in each call to the procedure and must take the form complex(a,-b) (where a is the real part of the refractive index, and b is the imaginary (or absorptive) part, and is either zero or negative).`Dqv`: Cosines of the scattering angles at which to calculate the intensity functions etc. If specified it**must**be vector of type float or double (although it can have only one element).`Npts=Npts`: If set, this keyword overrides the default calculation of the quadrature points (which provides points at 0.1 spacing in the size parameter).**Note:**Great care should be taken when using this keyword, as reducing the number of quadrature points will decrease the accuracy of the result.`xres=xres`: Sets the spacing of the quadrature points (in size parameter). Overridden by`Npts`. Default is 0.1..**Note:**Great care should be taken when using this keyword, as reducing the number of quadrature points will decrease the accuracy of the result.`/DLM`: If set the IDL DLM version of the algorithm (`mie_dlm_single`) will be used instead of the IDL coded version. Note: This requires the DLM to be compiled.`mthread=mthread`: Controls the number of threads which will be utilised by the DLM version of the algorithm. If not set by default the code will use 1 thread. See the procedure header for more information.`/SILENT`: If set all warning messages issued by the code will be suppressed.
`Bext`: Total extinction coefficient of the distribution. This will be a scalar of type double and the units will be determined by those of number density and particle size (see here for further explanation).`Bsca`: Total scattering coefficient of the distribution. This is of the same type and size, and will have the same units as`Bext`.`w`: Single scatter albedo of the distribution. This is of the same type and size as`Bext`.`g`: Asymmetry parameter of the distribution. This is of the same type and size as`Bext`.`SPM`: Scattering phase matrix elements F11 (F[0,*]), F33 (F[1,*]), F12 (F[2,*]), F34 (F[3,*]), where the 2nd dimension is the same dimension as Dqv. This will only be calculated if`Dqv`is specified.`Bbac`: Total backscatter coefficient of the distribution.`Gavg`: Average projected area per particle of the distribution.`Vavg`: Average volume per particle of the distribution.`Ravg`: Average radius of the distribution.`RVW`: Volume-weighted average radius of the distribution.`info`: Named variable that, on return, will contain a structure containing the number of abscissa points and the maximum and minimum size parameters used.
## Limitations and dependencesThis procedure calls the This procedure also calls the
## Download source codeThe source code for this routine and supporting routines is part of the EODG Mie scattering distribution which may be downloaded as a gzipped tar file here.Maintained by Greg McGarragh |
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Earth Observation Data Group, Department of Physics, University of Oxford. | Page last updated: @15:18 GMT 07-Jun-2022 | |