Minimize Processing Overview - Earth Observation Mode

OLCI Level-1 Earth Observation Processing

OLCI Level-1 Earth observation processing mainly involves calibrating the numerical counts contained in Instrument Source Packets (ISPs) into radiances, geo-locating acquired pixels on the Earth's surface and re-sampling the image onto an orthogonal product grid representing the instrument ideal swath. In addition, quality flags, meteorological annotations and pixel classification flags are computed and appended to the output Level-1B products.

This processing involves the following steps:

  1. Data extraction and quality checks.
  2. Radiometric scaling.
  3. Stray light correction.
  4. Georeferencing.
  5. Pixel classification functions.
  6. Spatial re-sampling.
  7. Product formatting (not described here).

Note: Since no Level-1A product is generated, the entire Earth observation processing is considered to be Level-1B (no specific Level-1A processing step is defined).

OLCI Level-1 Earth Observation Processing Top Level Breakdown

Note: The abbreviations represent specific OLCI ADFs:
IC = Instrument Characterisation
RC = Radiometric and spectral Calibration
DEM = Digital Elevation Model of the Earth's surface, assumed embedded in the mission software CFI
LWCM = Land/Water/Coastline Map
CT = bright and glint Classification Thresholds
MD = Meteorological Data
OF = Orbit File (source for time correlations but also for navigation in case NAVATT Level-0 is not available as input).