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  mie_single
  mie_lognormal
  mie_derivs
  mie_derivs_ln
  mie_dlm_single
  mieext_f
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mie_single.pro


Purpose

The mie_single.pro routine performs single particle Mie scattering calculations, providing the distribution of scattering radiation, as well as various particle cross sections and the asymmetry parameter.

Calling the procedure

mie_single.pro is an IDL procedure and can be called with the following command line from the IDL prompt (as long as the source file lies within your IDL_PATH environment variable):

mie_single, Dx, Cm, [Dqv=dqv], Dqxt, Dqsc, Dqbk, Dg, Xs1, Xs2, Dph, /dlm

The input parameters in the above call are:

  • Dx: The particle size parameter(s). This can either be a scalar float/double quantity or a vector of values and must always be greater than zero.
  • Cm: The complex refractive index of the particles. 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 absorpative) part, and is either zero or negative).
  • Dqv=dqv: This is an optional keyword parameter which specifies the cosine of the scattering angles at which to calculate the phase function. If specified it must be either a scalar quantity, or a vector of such values.
  • dlm=dlm: If set the IDL DLM version of the algorthim (mie_dlm_single) will be used instead of the IDL coded version. Note: This requires the DLM to be set up on your system!
The output parameters are:
  • Dqxt: The extinction efficiency. This will be a vector of type double, with the same number of elements as Dx.
  • Dqsc: The scattering efficiency. This is of the same type and size as Dqxt.
  • Dqbk: The back-scatter efficiency. This is of the same type and size as Dqxt.
  • Dg: The asymmetry parameter. Again, this is of the same type and size as Dqxt.
  • Xs1: The first amplitude function - amplitude of light polarized in the plane perpendicular to the directions of incident light propagation and observation. Xs1 is a complex array of dimensions the no. of elements in Dqv by the no. of elements in Dx. It is only calculated if Dqv is specified.
  • Xs2: The second amplitude function - amplitude of light polarized in the plane parallel to the directions of incident light propagation and observation. Xs2 is of the same type and size as Xs1 and is also only calculated if Dqv is specified.
  • Dph: The phase function. This is of type double and has the same dimensions as Xs1 and Xs2 and is also only calculated if Dqv is specified.

Limitations and dependences

The maximum size parameter allowed by mie_single.pro is 1200. Any value larger than this will result in the programme halting with the error message "Error: Size Parameter Overflow in Mie".

To allow the use of the dlm keyword the IDL DLM mie_dlm_single must be installed and set up on your system.

This procedure is called by the mie_lognormal.pro and mie_derivs_ln.pro procedures.

Download source code

The source code for this routine can be downloaded in gzip form from here.
last updated @16:54 GMT 08-Nov-2010 printable version