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SciaL1C Command-line Tool

The SCIAMACHY Calibration and Extraction Tool (SciaL1C) is an application software for processing SCIAMACHY Level 1b products.

This tool enables users to selectively apply specific calibrations to SCIAMACHY Level 1b data, which consists of partially calibrated Level 0 channel information combined with calculated calibration data. 

What is SciaL1C?

  • Calibration and extraction tool for SCIAMACHY Level 1b data
  • Command-line based utility, allowing batch processing
  • UNIX-like syntax, e.g. SciaL1C –option1 –option2   L1b-product-name

System requirements

SciaL1C version 4.2 (static binary file) is available for Linux AMD 64-bit platforms using x86 architectures (x86_64-pc-linux-gnu).

What can the SciaL1C tool do?

A complete description of the SciaL1c functionalities can be found in the SciaL1C Command-line Tool Software User Manual.

Main features include:

  • Listing all measured states in a Level 1b product
  • Extracting data sets from a Level 1b product – selecting on:
    • measurement time
    • geolocation
    • data set type (e.g. Nadir, Limb, Monitoring)
    • refined selection options within a data set (see below)
  • Performing Level 1b to Level 1c processing with options to:
    • apply all default calibrations, or
    • apply only specified calibrations.

New features incorporated in the latest release (v4.2):

  • Read Level 1b NetCDF products version 10 and generate NetCDF Level 1c products
  • New Moon option type for Level 1b V.10 products. Option to copy lunar data to Level 1c product

Selection options within a data set:

  • Extract data containing a specific SCIAMACHY Measurement Category
  • Extract data from user-specified clusters (i.e. spectral ranges, this requires knowledge of the SCIAMACHY cluster configuration available from SOST website)
  • Extract PMD measurements
  • Extract fractional polarisation values

Selection of calibration options:

No calibration – do not apply any calibration step (DEFAULT)
0 =  memory - application of memory effect (channel 1-5) and non-linearity (channel 6-8)
1 =  leakage - application of dark signal correction
2 =  ppg -  application of Pixel-to-Pixel Gain
3 =  etalon - application of etalon correction (channels 1-5). Option no longer maintained. Since etalon correction is already contained in the m-factor correction and applied to the Level 1b products since baseline version 8, this calibration step is skipped selecting –cal all and –allcal. Option compat permits to force usage of etalon correction.
4 =  straylight - application of stray-light correction
5 =  spectral - application of wavelength calibration
6 =  polarisation - application of polarisation correction
7 =  radiance - application of radiometric calibration
8 =  sun - PMD sun normalisation
mfactor =  mfactor - application of M-factor file. Option no longer maintained. Since degradation correction is already directly applied in Level 0-1 processing since baseline version 8, this calibration step has to be forced with the new compatibility option.
all =  allcal - application of all calibrations (0-8 but etalon)

Installation and syntax example

The SciaL1C software is provided as binary executable file. It only requires to be copied into an appropriate path on your platform (for example /usr/bin or some other convenient path which is set in your PATH variable), and to be started launching the scial1c command with proper options (or you may alias to the installation path and tool name with an alias name).

Syntax examples are provided within the Software User's Manual. As an example, to select and fully calibrate all Nadir and Limb data (measurement categories 1 and 2) in SCIAMACHY channel 3, select option: –cat 1,2 –nadircluster 17,18,19,20,21,22,23  –limbcluster 13 –allcal

Input data

The SciaL1C version 4.2 tool is designed for use with the new SCIAMACHY Level 1b baseline version 10 products, but it is still downwards compatible, and the old SCIAMACHY Level 1 version 8 products can still be read and written.

For testing, download a sample Level 1b version 10 product: EN1_RPRO_SCI_____1P_20020802t193334_20020802t211402_002215_01_100000_20240215t233011.nc.zip (288 MB)

The entire SCIAMACHY Level 1b version 10 dataset, resulting from the full-mission reprocessing campaign completed in 2023 is freely available for download to anyone with an ESA EO Sign In account via the online Dissemination service for ESA Heritage Missions (HM) Atmospheric data.

M-Factors are used for the correction of instrument degradation affecting the light path. Starting from SCIAMACHY Level 1 processing baseline version 8, M-Factors are already applied to the Level 0-1b processing step and enclosed into the Level 1b products. The external input of M-factor files (provided by the University of Bremen) is thus no longer required.

Download

Executable files (Version 4.2):

References:

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