Minimize Meteorological Annotations

Meteorological annotation processing aims to compute the meteorological parameters, time-sorted and colocated with the tie-points grid given at a resolution of 16 km, in order to enable further processing at Level-2. Firstly, it applies a temporal interpolation between the values available before and after the mid-exposure time of the product. Secondly, a spatial bilinear interpolation is applied on each tie-point location to retrieve all parameters of interest on this grid.

According to the interval of time separating the input data contained within the meteorological ADF, a Product Confidence Data (PCD) is computed enabling estimation of the level of accuracy of the embedded meteorological data with regard to the expected timeliness of the meteorological input data delivery. In addition, some parameters are directly provided from time series (-18, -12, -6, 0, 6) of ECMWF files, i.e. without interpolating the data at mid product time.

Before this step, a tie-point interpolation is performed. This processing has two main objectives:

  • Delimitate the rectangular SLSTR Level-1B image
  • Go from 16 km resolution to 1 km resolution in the along-track direction for the tie-point grid
Logical flow of meteorological annotation computation