data.sd.scattering takes (or requests from data.get) a size distribution (as a set of dN/dLogDp values, in cm^-3) and a set of bin diameters (in um) and calculates optical scattering, backscattering and absorption from it. It can optionally read a file with refractive indexes for each bin or a single one for all bins. Normally it generates a large table of Mei efficiency factors and uses linear interpolation between the two bracketing alpha values, however, there is an option to generate the factors for each time step.
data.sd.optical.calc can be used independently or as part of the list of sources data.get uses.
Command Line Usage
data.sd.optical.calc [--wls=wl1,wl2,wl3] [--wla=wl1,wl2,wl3] [--skipbins=0] [--ri=<re,im>|<file>] [--recalc-mei] station record start end [source]
data.get ... | data.sd.optical.calc [--wls=wl1,wl2,wl3] [--wla=wl1,wl2,wl3] [--skipbins=0] [--ri=<re,im>|<file>] [--recalc-mei]
start and end
The time specifiers for the data to be retrieved. Start is inclusive while end is exclusive, so all data contained within the half open interval [start,end) will be returned. Any convertible time format is accepted.
The station identifier code. For example 'brw'. Case insensitive.
The cpd2 record type to be retrieved. Must end with a 'c' for records such as 'N12c'.
Set source archive to request data from.
Wavelengths to calculate (back)scattering for, in nm. By default 450, 550, 700.
Wavelengths to calculate absorption for, in nm. Defaults to none (absorption not calculated).
Skip the first N bins.
Set the source for the refractive indexes. Can be set as either a path to a file name (with one entry per line) or a pair of a real and imaginary component as a constant for all bins. Defaults to 1.53,0.001.
Recalculate the Mei efficiency factors for every time step (gives more accurate values when the bin diameters change).
data.sd.optical.calc brw N22c 2008:10 2008:11