SCIAMACHY level 1c tools

Conversion tools for SCIAMACHY level 1c calibrated spectra to be used for trace gas retrieval with scia_retrieval_2d.

This package currently supports the following level 1c conversions for limb and solar reference spectra (.l_mpl_binary does not apply to the solar spectra):

type	read	write
.dat	yes	yes
.l_mpl_binary	yes	yes
.nc	yes	yes
.h5	yes	no

This is no level 1b to level 1c calibration tool!

For calibrating level 1b spectra (for example SCI_NL__1P version 8.02 provided by ESA via the ESA data browser) to level 1c spectra, use the SciaL1C command line tool or the free software nadc_tools. The first produces .child files, the second can output to HDF5 (.h5).

Note: .child files are currently not supported.

Install

The sciapy level 1c module is part of sciapy whose installation is described in the main README.

Usage

A simple documentation it provided using pydoc:

$ pydoc sciapy.level1c

This packages provides a submodule level1c with the following classes

• scia_limb_scan to handle calibrated SCIAMACHY level 1c limb scan spectra
• scia_solar to handle calibrated SCIAMACHY solar reference spectra

The submodule documentation can also be accessed with pydoc:

$ pydoc sciapy.level1c
$ pydoc sciapy.level1c.scia_limb_scan
$ pydoc sciapy.level1c.scia_solar

Examples

Convert a level1c ascii limb spectral file to binary format for scia_retrieval_2d:

>>> import sciapy
>>> scia_limb_scan = sciapy.level1c.scia_limb_scan()
>>> scia_limb_scan.read_from_textfile("/path/to/limb_state_filename.dat")
>>> scia_limb_scan.write_to_mpl_binary("/path/to/limb_state_filename.l_mpl_binary")

Using nadc_tools to convert to HDF5 and then save to ascii spectral files:

# calibrate and save to HDF5 first
$ /path/to/nadc_tools/bin/scia_nl1 -limb -no_gads -no_ads --cat=26,27 --channel=1 --cal=1,2,4,5+,6,7,9,E,N -hdf5 -compress /path/to/L1b_v8.02/SCI_NL__1PYDPA.N1 --output=SCI_NL__1PYDPA.N1.ch1.h5

within python the rough steps are:

>>> import h5py
>>> import sciapy
>>> h5file = h5py.File(args.file, "r")
>>> scia_limb_scan = sciapy.level1c.scia_limb_scan()
>>> scia_limb_scan.read_from_hdf5(h5file, limb_state_id, id, cluster_ids)
>>> scia_limb_scan.write_to_textfile("/path/to/limb_state_filename.dat")

For a more complete example which also extracts the solar reference spectrum, see the accompanying scia_conv_hdf5_limb.py script.

A simple conversion tool is provided with the scia_binary_util.py script.