Minimize Level-1

The OLCI Level-1 data is divided into four product packages (two of which are internal products). Each is composed of an information package map, also called a manifest, and several measurement and annotation data files.

  • OL_1_EFR, providing the OLCI Level-1 full resolution product, includes 22 measurement data files and seven annotation data files.
  • OL_1_ERR, providing the OLCI Level-1 reduced resolution product, includes 21 measurement data files and seven annotation data files.
  • OL_1_RAC, providing internal dark offset and gain coefficient from radiometric calibration: includes one measurement data file and one annotation data file.
  • OL_1_SPC, providing internal wavelength characterisation from spectral calibration: includes one measurement data file and two annotation data files.

For full resolution and reduced resolution products, the measurement files are written in netCDF 4 format and contain the TOA radiances and their error estimates for each OLCI channel (21 channels).

OL_1_EFR is also composed of one file providing data for each removed pixel, the 21 associated radiances, geographical position, associated angles and flags.

The annotation data files, also written in netCDF 4 format, are similar and described in the following table.

File Name Dimensions Contents
timeCoordinates Number of lines in the product image Time stamp
geoCoordinates Number of lines and columns in the product image. Longitude, latitude, altitude.
qualityFlags Number of lines and columns in the product image. Quality flags.
tie_geoCoordinates Number of lines and columns in the tie-point grid. Longitude, latitude.
tie_geometries Number of lines and columns in the tie-point grid Sun and observation angles.
tie_meteo Number of lines and columns in the tie-point grid. ECMWF data.
instrumentData Number of lines and columns in the product image, number of instrument detectors per frame and number of OLCI bands. Detector Index, OLCI channels central wavelength and bandwidth, solar irradiance.

Table 1: Description of annotation data files included in OLCI user products

For calibration products, the content is similar, written in netCDF 4 and described in the following table.

File Name Product File Type Dimensions Contents
radiometricCoef OL_1_RAC Meas. Number of instrument detectors, number of OLCI band and number of dark and blank pixels. Dark offsets and currents
coefficients; gain coefficients and time average of the dark/blank pixels acquired in shutter or diffuser position.
RC_annotations OL_1_RAC Annot. Number of instrument detectors, number of OLCI band and number of OLCI cameras. Quality flags, valid acquired
pixels used in different computation and statistics of CCD temperature in shutter or diffuser position.
calWavelengths OL_1_SPC Meas. Number of used frames, of selected row, number of instrument detectors, of OLCI camera and number of dark/blank pixels. Central wavelengths, time average of the dark/blank pixels acquired in shutter or diffuser position.
TimeCoordinates OL_1_SPC Annot. Number of used frames. Time stamps.
SC_annotations OL_1_SPC Annot. Number of used frames, of selected row, of instrument detectors and of OLCI camera. Quality flags and statistics of CCD temperature in shutter or diffuser position.

Table 2: Description of OLCI Level-1 product from calibration processing

Associated with each file, an information package map describes the content unit identifier and description, and the type of data contained in each file. An XML manifest file contains metadata associated with the instrument and the processing.