# Mie Scattering 3D: What does the raw data describe?

#1

My question pertains to the raw files included in this example. The file mie_au_jc_fdtd.txt is the theoretical Mie scattering cross sections (absorption and scattering) calculated for the material fit and the file mie_au_jc_raw.txt is that for the sampled data. In these files, there are 3 columns of data. What property does each of the columns correspond to?

I first assumed that the 1st column corresponds to the wavelength range and the 2nd and 3rd are the absorption and scattering cross sections, respectively. But the wavelength range doesn’t correspond to 300nm-600nm in the simulation. There aren’t column headings in the file that describe the data.

I am attempting to plot this data in Matlab, but need to know which column is what.

Thanks so much for your help,
Chris

#2

Hi Chris,

In this example, we calculate the Mie efficiency for the scattering cross section and the absorption cross section. The MIe efficiency is defined as the ratio of cross_section of scattering/absorption and the geometrical area pir^2; and the size parameter is 2pi*r/lambda. These are the data in the 2 txt files, calculated from the Mie theory.

I hope this helps.

Greg

#3

Hi Greg,

Thanks for this information. This is helpful. But my actual question is which of the 3 properties correspond to the 3 columns in the .txt file. There are no column headings. I hope that my question is clear.

Are you saying that the 3 columns are the Mie efficiency, geometrical area and the size parameter? (This doesn’t seem to be the case.)

Thanks for your help,
Chris

#4

Hi Chris,
Sorry, I didn’t put that in the right order, the 3 columns should be the size parameter, Mie efficiency (scattering cross section) and Mie efficiency (absorption cross section).
I sure agree it would be easier if the files had headers! I’ll ask my colleagues to change that.

Greg