Minimize Spectral Response Function Data

In the frame of pre-launch activities for Sentinel-3's OLCI-A instrument, a first version of the instrument Spectral Response Functions (SRFs) based on on-ground characterisation measurements was derived. The spectral characterisation information is provided in the following three files with three different levels of detail:

  • The full dataset - Includes for each of the 21 OLCI-A spectral bands, the centre wavelength, the bandwidth and the in-band solar irradiance at individual OLCI CCD columns (corresponding to the across track dimension of the instrument swath)
  • A subset of the dataset - The same as the full file, but reduced to the spectral response functions at only three CCD columns (located at Eastern, centre, and Western part) for each module and each one of the 21 spectral bands
  • The mean dataset - The same as the full file, but reduced to a single representative (mean) spectral response function, in-band solar irradiance, bandwidth and centre wavelength per band.

The way the data are generated and the underlying theoretical model are described in this Technical Note.

Note: Further calibration and validation activities are planned in the frame of the Sentinel-3A Commissioning Phase. These activities should allow verifying the in-flight performance of the instrument. It is in particular foreseen to review the pre-launch instrument spectral characterisation measurements from which the present SRFs are derived. If deemed necessary, an update of the SRFs might thus be provided at the In-Orbit Commissioning Review (IOCR), 5 months after the launch. Moreover, the spectral characteristics of OLCI-A will be monitored through the entire mission duration and this might again lead to updates of the instrument SRFs at a later stage in the mission lifetime.