Table Processing (Formerly Scripting)
For some purposes it is desired to calculate radiometric quantities for a set of geometries (e.g. variation of the elevation angle), wavelengths (e.g. spectra calculation) or atmospheric states (e.g. sensitivity analysis w.r. to aerosol properties). In the former version of McArtim this was the "script feature".
For these cases McArtim can be invoked with the -t command line switch. In that
operation mode McArtim will evaluate the file
use settings from that file found in each row and process radiometric
quantities accoding to these settings. The format (i.e. the columns) of the
is described by the file
fn_table_description. It must have as many rows
as there are columns in
fn_data_table. In principle all parameters
supplied to McArtim can be accessed through an expression
At the moment only the geometry object, atmospheric constituent profiles and the wavelength supplied in
simulation.confhave been tested for their correct functionality in the table processing operation mode. There are two more keywords
ignorethat are needed in most cases.
Suppose that one wants to calculate radiances at a certain wavelength for a set of geometry parameters given at certain times, e.g. the telescope elevation angle the solar zenith angle and the relative solar azimuth angle for a series of time points. The geometries data file could look like
According to the
fn_table_descriptionthe data file
fn_data_tablehas five columns of which the first and the second (
carry) are carried over to the output line. The other opportunity is the
ignorekeyword by use of which the data in the respective column are simply ignored. In the example above, the last three columns (3, 4 and 5) are the telescope elevation angle and the two relevant solar position angles.
Accessing Atmospheric Constituent Profiles
Gas number densities or particle optical properties can be accessed through the following syntax:
name.profile[cluster index, parameter index]
It is important to use the
namethat is passed to the constituent object defintion file in the
cluster indexselects the cluster, and
parameter indexwill specify the cluster parameter that shall be modified. For gases only 1 is allowed, particle optical parameter indices range from 1(ext.), 2(ssa), 3(g), 4(h) to 5(p) or more depending on which phase function model is used. For example NO2.profile[3,1] for example will access the number density of NO2 in cluster 3 and HG.profile[7,3] accesses the asymmetry parameter of the particle named "HG" in cluster 7.