Minimize Software tools

SciaL1C Command-line Tool

 

The SciaL1C tool is an application provided to the users of SCIAMACHY Level 1b products.
This application allows users to select specific calibrations to apply to Level 1b data, which are in the 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 about the SciaL1C tool compared to the version distributed with EnviView?  

  • 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
  • Version for Windows operating system now available

Note that the Scial1C tool provided with EnviView shall not be used for SCIAMACHY Level 1b data of version 6 or above.


Major changes and improvements in Version 2.1 with respect to Version 1.24

  • M-Factor Application:
    • M-Factors are used for correction of instrument degradation affecting the light path. With the new version it is possible to apply m-factors. As external input the M-factor files are needed, which are provided by the University of Bremen. Two options are supplied:
      • Automatic selection of the correct file using the same rules as the operational processor
      • Manual selection of the m-factor file by the user
  •  
  • Data set (DS) selection and Level 1c generation was improved (option -ds)
  •  
  • The listing of states (option -list) now recognises filter options
  •  
  • Comments in batch files are now possible
  •  
  • Improved error logging for easier tracking of issues
  •  
  • Experimental ASCII output possible (options -ascii, -ascii-smr) originally developed for debugging. User feedback on this feature is appreciated

See the SciaL1C Software Release Notes for a complete listing of all changes


System Requirements

  • LINUX Kernel 2.4.x or 2.6.x or higher
  • Sun Solaris OS 5.8 or higher 
  • HP-UX Version 11.23 or higher
  • LINUX under DEC-Alpha alphaev67-pc-linux-gnu or higher
  • Windows


What can the SciaL1C tool do?

A complete description of the SciaL1C functionalities can be found in the SciaL1C Software User’s Manual. Features include:

  • 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 calibration


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 =  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 Files

all =  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


Executables (Version 6.0 Revision 2.1)


Sample Data

The Level 1b sample data provided here was produced with the prototype which is in-line with the SCIAMACHY Level 1b Version 6.02 baseline.


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