The DUACS (Data Unification and Altimeter Combination System) system processes data from different altimeter missions to provide a consistent and homogeneous catalogue of sea level products and derivate variables for a wide range of applications, both for near real time (NRT) applications and delayed-time (DT) studies.
The DUACS processing steps are summarized in the following figure.
L2P upstream data
Acquisition and data selection
Homogenization and cross-calibration
Along-track (L3) products generation
Merged gridded (L4) products generation
Derived products and quality control
To read more about the DUACS processing, you can also see Pujol et al, 2016