SciaL1C Command-line Tool

The SciaL1C tool is an application provided to the users of SCIAMACHY Level 1b products. This application allows to select specific calibrations to apply to Level 1b data, which are in case of SCIAMACHY defined as not fully calibrated Level 0 channel information in combination with calculated calibration data. The generated Level 1c products are suitable for the user’s particular applications.

 

This new tool is a replacement for the SciaL1C tool provided with EnviView. 

What is SciaL1C 

• Calibration and extraction tool for SCIAMACHY Level 1b data
• Command-line based utility
• UNIX-like syntax, e.g. SciaL1c –option1 –option2   L1b-product-name
• Batch processing is possible 

What is  new with the  SciaL1C tool as compared to the previous version 

• Stand-alone program, replacing the earlier L1c tool delivered with EnviView
• Up-to-date algorithms, synchronised with the latest IPF version developments
• Downward compatible to products generated by IPF 5.04 or 4.32
• Windows operating system  currently not supported 

System Requirements 

• LINUX Kernel 2.4.x or 2.6.x or higher
• Sun Solaris OS 5.8 or higher 

What can the SciaL1C tool do 

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

Selection options within a data set 

• Extract data containing a specific SCIAMACHY „Measurement Category“
• Extract data from user-specified clusters (spectral windows)
• requires knowledge of SCIAMACHY cluster configuration
  (can be found on SOST website)
• Extract PMD measurements
• Extract fractional polarisation values  

Selection of Calibrations 

The following calibration options exist:

no_calibration – don’t apply any calibration step (DEFAULT)

0 =  memory - application of memory effect (channel1-5) 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)

4 =  spectral - application of wavelength calibration

5 =  straylight - application of stray-light correction

6 =  polarisation - application of polarisation correction

7 =  radiance - application of radiometric calibration

8 =  allcal - application of all calibrations 

Syntax Example 

• The syntax follows that of the earlier program delivered with ENVIVIEW
• For example, to select and fully calibrate all Nadir and Limb data (measurement category 1 and 2) in SCIAMACHY channel 3, select  as options:

–cat 1,2 –nadircluster 17,18,19,20,21,22,23  –limbcluster 13 –allcal 

References 

• SCIAMACHY Level 1b-1c Processing The SciaL1c Command-line Tool Software User’s Manual, ENV-SUM-DLR-SCIA-0071
• Johannes Frerick, “Sciamachy Level 1C Product”

Executables (Status: 07 June 2006)

• Linux
• Sun Solaris 

Installation 

• copy the software into an appropriate path on your platform (for example /usr/bin or some other convenient path which is set in your PATH variable)
• start the software with the command scial1c or you may alias to the installation path and tool name with an alias name