mie

Mie code to calculate light scattering by perfect spheres.

https://github.com/scottprahl/mie

Repository

Mie code to calculate light scattering by perfect spheres.

README.rst

.. |github| image:: https://img.shields.io/github/v/tag/scottprahl/mie?label=github&color=68CA66
   :target: https://github.com/scottprahl/mie

.. |license| image:: https://img.shields.io/github/license/scottprahl/mie?color=68CA66)
   :target: https://github.com/scottprahl/mie/blob/main/LICENSE

.. |docs| image:: https://img.shields.io/badge/docs-passing-68CA66
   :target: https://github.com/scottprahl/mie/blob/main/doc/mie_doc.pdf

.. |test| image:: https://github.com/scottprahl/mie/actions/workflows/test.yaml/badge.svg
   :target: https://github.com/scottprahl/mie/actions

.. |zenodo| image:: https://zenodo.org/badge/DOI/10.5281/zenodo.10087653.svg
   :target: https://doi.org/10.5281/zenodo.10087653

|github|  |license| |docs| |test| |zenodo|

Mie Scattering
==============

Mie Scattering is a method for simulating the scattering of
electromagnetic waves (light) by spheres. Based on the robust FORTRAN
implementation by Warren Wiscombe, this software offers researchers and scientists an accurate
and reliable tool for Mie scattering calculations.

Features
--------

- Accurate simulation of scattering for small to very large sphere sizes (𝜋d/λ > 10,000)

- Tested against `MIEV0 `_ implementation

- Used to a `web-based Mie calculator `_

The source code is written in `CWEB `_, which
allows excellent documentation of scientific programs. Basically, there is a
program ``ctangle`` that converts cweb code to C. There is another program
``cweave`` that converts cweb code to TeX. This then generates `nicely
documented source code `_.

Getting Started
---------------

Downloading
~~~~~~~~~~~

Clone the repository using git or download the source code as a zip file:

.. code-block:: shell

    git clone https://github.com/scottprahl/mie.git

Installation
~~~~~~~~~~~~

Unix/macOS
^^^^^^^^^^

Run the following command to build and install:

.. code-block:: shell

    make install

The executable will be installed as ``/usr/local/bin/mie``.

Windows
^^^^^^^

Download the latest executable from the `Releases page `_.

Python Package
^^^^^^^^^^^^^^

I have written a pure python version of Mie scattering based on this code.
`miepython `_ is a bit slower, but it 
allows one to run simulations in `jupyterlab `_ interactively.  
Installation is easy: 

.. code-block:: shell

    pip install miepython

Usage
-----

Here is a simple implementation that calculates scattering parameters from 360 nm latex
spheres by UV-A light.

.. code-block:: c

    #include 
    #include 
    #include "mie.h"

    int main() {
        const double n_sphere = 1.59;
        const double n_medium = 1.34;
        const double diameter_nm = 360;
        const double sphere_density = 1.05; // gm/ml
        const double medium_density = 1.00; // gm/ml
        const double concentration = 0.01; // gm spheres/gm medium
        double x, qsca, g, sphere_area_cm2, sphere_volume_ml, number_per_cc, lambda_nm;

        printf("Sphere concentration is          %5.2g%% gm spheres/gm\n", concentration * 100);
        printf("Medium refractive index is       %7.4f\n", n_medium);
        printf("Sphere refractive index is       %7.4f\n", n_sphere);
        printf("The density of the spheres is    %7g gm/ml\n", sphere_density);
        printf("The density of the medium is     %7g gm/ml\n", medium_density);
        printf("\n");
        printf("    d    lambda     x      N       Q_sca    g      mu_s    mu_s'\n");
        printf("  [nm]    [nm]     [-]   [#/ml]     [-]    [-]    [1/cm]  [1/cm]\n");

        for (lambda_nm = 315; lambda_nm <= 400; lambda_nm += 5) {
            x = (diameter_nm * M_PI) / (lambda_nm / (n_sphere / n_medium));
            sphere_area_cm2 = M_PI * pow(diameter_nm / 1e7, 2) / 4.0;
            sphere_volume_ml = M_PI * pow(diameter_nm / 1e7, 3) / 6.0;
            number_per_cc = 1 / (sphere_volume_ml * (1 + sphere_density / (medium_density * concentration)));
            ez_Mie(x, n_sphere / n_medium, &qsca, &g);

            printf("%7.1f %7.1f ", diameter_nm, lambda_nm);
            printf("%7.2f %7.2e %7.4f %7.5f ", x, number_per_cc, qsca, g);
            printf("%7.2f ", qsca * sphere_area_cm2 * number_per_cc);
            printf("%7.2f \n", (1 - g) * qsca * sphere_area_cm2 * number_per_cc);
        }
        return 0;
    }

When compiled (see ``src/Makefile`` for details), this produces::

    Sphere concentration is              1% gm spheres/gm
    Medium refractive index is        1.3400
    Sphere refractive index is        1.5900
    The density of the spheres is       1.05 gm/ml
    The density of the medium is           1 gm/ml

        d    lambda     x      N       Q_sca    g      mu_s    mu_s'
      [nm]    [nm]     [-]   [#/ml]     [-]    [-]    [1/cm]  [1/cm]
      360.0   315.0    4.26 3.86e+11  1.1711 0.86861  460.32   60.48 
      360.0   320.0    4.19 3.86e+11  1.1360 0.86600  446.54   59.84 
      360.0   325.0    4.13 3.86e+11  1.1024 0.86347  433.34   59.16 
      360.0   330.0    4.07 3.86e+11  1.0703 0.86102  420.70   58.47 
      360.0   335.0    4.01 3.86e+11  1.0395 0.85866  408.62   57.75 
      360.0   340.0    3.95 3.86e+11  1.0101 0.85640  397.04   57.02 
      360.0   345.0    3.89 3.86e+11  0.9818 0.85422  385.92   56.26 
      360.0   350.0    3.83 3.86e+11  0.9546 0.85212  375.22   55.49 
      360.0   355.0    3.78 3.86e+11  0.9282 0.85006  364.87   54.71 
      360.0   360.0    3.73 3.86e+11  0.9027 0.84803  354.83   53.93 
      360.0   365.0    3.68 3.86e+11  0.8779 0.84597  345.08   53.15 
      360.0   370.0    3.63 3.86e+11  0.8537 0.84384  335.59   52.41 
      360.0   375.0    3.58 3.86e+11  0.8302 0.84159  326.35   51.70 
      360.0   380.0    3.53 3.86e+11  0.8074 0.83919  317.36   51.04 
      360.0   385.0    3.49 3.86e+11  0.7851 0.83658  308.62   50.43 
      360.0   390.0    3.44 3.86e+11  0.7635 0.83375  300.13   49.90 
      360.0   395.0    3.40 3.86e+11  0.7426 0.83065  291.91   49.43 
      360.0   400.0    3.35 3.86e+11  0.7224 0.82729  283.98   49.05 

License
-------

This project is licensed under the `BSD 3-clause License `_.

Citation
--------

If you use this software in your research, please cite it as below:

.. code-block:: bibtex

    @misc{prahl_mie,
      author = {Scott Prahl},
      title = {Mie Scattering},
      version = {v2.6.3},
      year = {2023},
      doi = {10.5281/zenodo.10087653},
      url = {https://github.com/scottprahl/mie}
    }

Owner

Citation (CITATION.cff)

authors:
- family-names: Prahl
  given-names: Scott
  orcid: https://orcid.org/0000-0003-1468-6851
cff-version: 1.2.0
date-released: '2023-11-09'
doi: 10.5281/zenodo.10087653
message: If you use this software, please cite it as below.
title: 'mie: command-line calculations of Mie scattering'
url: https://zenodo.org/doi/10.5281/zenodo.10087654
version: v2.6.3

GitHub Events

Issues and Pull Requests

Last synced: about 1 year ago