September 12, 2014

Operational Software

The objective of the OPS (OPerational Software) is to process IASI level 0 data, in near real-time, 7day/7 24 hour/24. This OPS will produce IASI level 1A, 1B and 1C data.

This software will be operated in Darmstadt (Germany) within EUMETSAT facilities. It will also be integrated in CNES Toulouse (France) inside the TEC (Technical Expertise Centre) which is a centre dedicated to IASI.

The OPS is composed of roughly fifty algorithms that are run in sequence. These algorithms process a set of IASI data which is called a granule (for example 3 minutes of level 0 data).

These algorithms are grouped into chains.

  • The first chain is the "IMAGE" one. This chain is dedicated to the decoding and the calibration of the data from the IASI imager.
  • The second chain is the "ISRFEM" chain. This chain processes the calibration computation.
  • The third chain is the "PRODUCT" chain, and is charged to generate IASI level 1 data.
  • The last chain: "MONITORING" is charged to survey the correct functioning of IASI OPS. The results of this chain are stored inside IASI engineering product (dedicated to IASI TEC)

The primary aim of IASI is to process level 1 data from level 0; but the reality is not so simple. As a matter of fact, IASI has to read a lot of types of input data, and has to write more than only level 1 data. The detail of the input/output data is detailed in the following figure:

Input/output data for IASI OPS


  • AVHRR is another instrument from METOP satellite
  • Context file contains data useful for a warmstart of the OPS
  • Verification data product is composed of IASI level 0 verification data added to the corresponding IASI level 0 data.