SCIAMACHY - Scanning Imaging Absorption Spectrometer for Atmospheric Chemistry


The Scanning Imaging Absorption Spectrometer for Atmospheric Chemistry (SCIAMACHY) instrument onboard of ENVISAT was designed to measure the atmospheric composition using different measuring techniques: nadir, limb and solar and lunar occultation.

Atmospheric Processors (AP) of DLR's Remote Sensing Technology Institute (IMF) operates the SCIA operational processor on behalf of ESA.


SCIA operational processor:


  • Level 0 to level 1b processor:

  • Level 0: Produced from the raw data, level 0 contains instrument source packets as received from the instrument with a small header attached by the Front-End Processor at the receiving stations.

  • scial1c: These are geolocated products in engineering or physical units. Level 1b products are generated by transforming the associated level 0 product via certain algorithms, calibration and auxiliary data.

  • Level 1b to level 1c:
  • Level 1c: Starting from level 1b products, i.e. uncalibrated spectra, calibration and auxiliary data, the scial1c tool merges all necessary data to obtain calibrated spectra (level 1c product).

  • Level 1b to level 2 processor:
  • Level 2: This is the highest product level supported by the ENVISAT PDS (Payload Data Segment). It represents the final geolocated geophysical product. The level 2 product is generated from the level 1b product by applying scientific algorithms to convert calibrated engineering quantities into geophysical parameters.

SCIA products:


SCIAMACHY products and various other satellite data products may be accessed at the following site:

ESA Earthnet: Data products

More documentation and data can be found at the ESA SCIAMACHY pages:

ESA: SCIAMACHY sensor-description

SCIA Tools:


  • scial1c:
  • Extracting and converting SCIA level 1b (uncalibrated plus calibration data) products to level 1c (calibrated spectra). Here is the official download site for this and other tools:

    ESA Earthnet: Software Tools

  • scial2toh5:
  • The data sets included in level 2 files do not contain an own geolocation record. Geolocation information is included in level 2 files as a stand alone (annotation) data set (ADS). This geolocation entry refers to the shortest integration time (IT) of all the measurement data sets (MDS) that are present in the level 2 product. Having only one geolocation data set (actually two, one for nadir and one for limb geometry observations) per level2 file saves a lot of storage space. Since the IT of all MDS's is a multiple of the shortest IT, the geolocation associated to a given MDS can be "straightforwardly" calculated from the geolocation at shortest IT. Unfortunately, there is no official software to do this conversion and new users have to face this problem time after time since the beginning of the mission.

    scial2toh5 has been developed at DLR to facilitate this task. It extracts an arbitrary MDS from a level 2 data set, composes the geolocation for its integration time and saves the data set with the geolocation information into a HDF5 file. It is written in python and uses CODA-BEAT for extracting the information from the level 2 files and PyTables for writing the HDF5 extracts. If you are a python programmer, maybe you are also interested in trying it interactively. It contains some basic functions and methods that could fit your necessities. You can find some brief documentation here about usage, installation and dependencies of the scial2toh5 tool. A tutorial on how to install Python, CODA-BEAT and scial2toh5 on a Windows computer can be found here: scial2toh5 installation tutorial

    Download scial2toh5