[INFO] Introduction of additional Radiometric Offset in PB04.00 products

Dear friends,

I write this to underscore the information in the Tables here
Processing Baseline - Sentinel Online and in the L1C and L2A Data Product Quality Reports - Sentinel Online

Along with several other evolutions, Processing Baseline 04.00 L1C (TOA) and L2A (BOA) products (TTO 25th of January, 2022) now contain an Offset in the metadata. This offset has been included to accomodate ‘noisy’ pixels over dark surfaces, that can sometimes present negative radiometric values at L1B and L1C.

Prior to PB 04.00, these negative values were clamped to a predefined range (e.g. [1-32767]), thereby leading to a loss of information. In order to avoid this, and following an analysis by expertise, a radiometric offset has been introduced which shifts the range. The conclusions of the analysis resulted in the following specifications for the Offset:

  • At L1B, RADIO_ADD_OFFSET = -100
  • At L1C, RADIO_ADD_OFFSET = -1000
  • At L2A, RADIO_ADD_OFFSET = -1000

SNAP is User-configurable for this change; the Radiometric Offset can be added in SNAP by selection of the relevant radio button (Tools > Options > Sentinel-2 Reader > Add negative radiometric offset (L1C -L2A) ):

image

Additional information can be found in the [Sentinel-2 Products Specification Document (PSD)](Sentinel-2 Products Specification Document (PSD) - Sentinel Online .)

I hope this information is of benefit to you.

Cheers

Jan

OPT-MPC S2 Technical Manager

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