1. Proposal for a new generation OST-VC User Requirements Document
P. Escudier and H. Bonekamp

2. Towards a new generation OST-VC
Implementation of the OST-VC constellation is well underway
Key role played by Copernicus sentinels complemented by other initiatives
OST-VC fulfils the needs of large-scale and larger meso-scale monitoring
Adequate to feed the current configuration of the Copernicus Marine Environment Monitoring Service as well as scientific uses.
However new societal, science and operational uses are emerging
A breakthrough improvement of the space and time resolution of the altimetry Virtual Constellation is required in a mid-term perspective
Models will soon be ready to analyze and predict ocean at a much smaller scale
 A new generation of constellation has to be defined
CNES, ESA and other agencies have initiated preliminary analyses
An encouragement from SIT Chair to EUMETSAT to support the development of this updated URD would be helpful

3. Current OST-VC roadmap
Launch
Date 15 16 17 18 19 20 21 22 23 24 25 27 13 14 26
Reference Nadir Missions (Non Sun-Synchronous)
20/08
Jason-2 FR/EU/USA
Jason-CS-A/Sentine-6-A EU/USA
JCS-B EU/USA
Jason-3 FR/EU/USA
Complementary Nadir Missions
02/13
Saral/AltiKa FR/Ind
Sentinel-3A EU
Sentinel-3B EU
Sentinel-3C EU
Sentinel-3D EU
04/10
CRYOSAT-2 EU
08/11
HY-2A CN
HY-2C CN
HY-2B CN
HY-2D CN
Broad-Coverage Mission
SWOT USA/FR
Compira jp
Operating
Development
Proposed
Feb 2016

4. Towards a new generation OST-VC
Current OST-VC space/time overall resolution:
~100 km, 10 days
Significant part of the ocean dynamics below 100 km
It will be better characterized thanks to new technology :
Higher along-track resolution on Sentinel-3 (delayed Doppler mode)
Wide-swath altimetry on SWOT (NASA/CNES) and COMPIRA (JAXA)
Comparison between drifting buoy trajectories and
currents deduced from current OST-VC

5. Towards a new generation OST-VC
Next steps
Confirmation by CEOS SIT of the interest to move forward to a higher resolution Ocean Surface Topography monitoring system to support the future generation of operational oceanography and new science and applications objectives
Analysis by various agencies of the different possible configurations: instrument technology, orbit configurations…
Analysis of these configurations and coordination by OST- VC group
Preliminary discussion at La Rochelle meeting
Encouragement from SIT Chair to EUMETSAT to support the development of an updated URD that would document this new configuration