MERCATOR OCEAN JOURNA: 
SEPTEMBER 2021 
3. POST 2021 PROSPECTS/ OUTLOOK 
The main drivers of the system evolution for coming years 
are following user needs, and include the continuity of the 
current service and the products improvement. 
The WAVE-TAC system will evolve based on the evolution of 
the constellations of altimetry, SAR and other radar missions 
measuring wave spectra (e.g., CFOSAT/SWIM off-nadir) to 
ensure a robust NRT sampling. Regarding the altimetry 
constellation, the following missions will be integrated: 
Sentinel-6A (2022), HaiYang-2C (2022), HaiYang-2D (2022), 
SWOT'’s nadir (2023), Sentinel-3C (2024). Concerning the 
SAR and other wave spectra measuring device constellation, 
the following missions will be integrated: CFOSAT/SWIM off- 
nadir (end 2021) and Sentinel-1C (2023). A particular effort 
will be made to improve the coverage of spectral wave 
parameter measurements along European coasts, using 
Sentinel-1 wide swath modes and other missions. 
Access to homogeneous long-term wave measurements is 
crucial for climate applications, assimilation in reanalyses 
and calibration/validation of wave hindcasts. Long-term 
reprocessing of altimetry missions will be disseminated by 
the end of 2021 based on the CCI Level-2P Sea state 
products and will be extended to SAR and other missions 
in the coming years. 
Finally, a particular focus will be on proposing higher 
resolution products thanks to new data processing. The 
ıncrease of along-track sampling will highly rely on: 
the noise reduction in upstream products (improved 
re-tracking, etc.), 
the improvement of along-track data selection to 
improve density and accuracy when approaching 
coasts, ice shelves or other complex areas, 
the processing of along-track 20-Hz upstream 
products into 5-Hz products (-1.4 km resolution), with 
adapted subsampling and filtering methods. 
All these proposed developments will be coordinated anc 
discussed with end-users during organized dedicatea 
meetings (TWAPAS). These will contribute to coordinate 
the research and development activities upstream of the 
different products as well as gather user's experience and 
needs on the already distributed ones. 
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