Algorithm Input and Output Data Definition (IODD)

Input data

Field	Description	Shape/Amount
L1B TB	L1B Brightness Temperature at C, KU and KA-bands (both H and V polarization)	full swath or section of it (Nscans, Npos)
L1B NeΔT	Random radiometric uncertainty of the channels	full swath or section of it (Nscans, Npos)

Output data

Field	Description	Shape/Amount
sea-ice concentration	The SIC between 0 and 1 (0: Open Water, 1: Consolidated Ice)	(Nscans, Npos)
raw sea-ice concentration value	SIC before Open Water Filter and thresholding (can be < 0 and > 1)	(Nscans, Npos)
sea-ice concentration total uncertainty	The retrieval uncertainty as 1-sigma	(Nscans, Npos)
sea-ice concentration uncertainty components	Several components of the retrieval uncertainty (TBD, e.g. radiometric uncertainty and algorithm uncertainty)	(Nscans, Npos)
status flags	indicates the reasons for missing, bad, or nominal SIC values.	(Nscans, Npos)

Tie-points: tie-points are generated offline (e.g. once a day) as part of the Level-2 SIC chain. They are thus by-product of the chain, that are stored and available for running the SIC chain on each CIMR orbit.

Auxiliary data

Auxiliary data will be required if RTM correction of the brightness temperature is activated. In that case, fields of T2m, T0m, Wind Speed, Total Column Water Vapour, Total Cloud Liquid Water, remapped to the dimensions of the swaths and collocated in time, will be required. They can for example come from ECMWF operational analysis and forecast system.

Ancillary data

Field	Description	Shape/Amount
land mask	A land mask	Remapped to dimensions of the swaths (can also be available in Level-1b files).
maximum ice	Climatological maximum ice coverage	Remapped to dimensions of the swaths.