1. Committee on Earth Observation Satellites
Virtual Constellation Issues, Discussion Points, and Decision Processes
Stephen Volz, NOAA CEOS SIT Chair
CEOS Plenary 2018
Agenda Item #6.6
Brussels, Belgium
17 – 18 October 2018

2. Three Elements 1
Collective Assessment by Members of the Virtual Constellations
Viability/Sustainability/Internal and External Connections
Resources
Agenda Item 4.3: Agencies reported on how CEOS, as an organization, is supporting and prioritizing engagement around the Agency’s requirements
Direction
Stronger focus on CEOS Work Plan and tracking of accomplishments 2 3

3. History of VCs
VCs were created to address gaps in missions and inform agencies on how to plan for future missions, maintain continuity of measurements and climate records, and avoid duplication and overlap in EO missions.
Four Prototype VCs created at SIT-19 (Sep 2006) to “give balance across different domains and geographies with an eye on leverage of international linkages to support continuity of funding for missions at the time which were under some threat”
Ocean Surface Topography (NOAA and EUMETSAT) Atmospheric Composition (NASA)
Land Surface Imaging (USGS) Precipitation (JAXA and NASA)
VCs circa 2018
“The interim goal of a Constellation is to demonstrate the value of a collaborative partnership in addressing a key observational gap; the end goal is to sustain the routine collection of critical observations. Implementation of Constellation activities is ultimately dependent on the coordination of formal agreements among participating agencies.” Virtual Constellations Process Paper 2013

4. SIT Chair Strategic Directions – VCs (and WGs)
Ensuring tangible outcomes from, and sustainable commitment to, our VCs and WGs
Maximizing the value of their output for CEOS objectives (e.g., ECVs and SDGs) and for individual CEOS Agency objectives
Ensuring the necessary support for our existing thematic teams to flourish and to deliver
Clearer overall CEOS observing system assessment and desired observing strategies – and known contribution from each CEOS Entity
STRATEGIC DIRECTIONS AND PARTNERSHIPS FOR CEOS
DISCUSSION PAPER – SIT-33

5. Dedicated Questionnaire to VCs, WGs, and Former VC and WG Leadership
January 2018
SIT Chair-VC/WG Tag-ups
February 2018 1

6. Review of VC/WG Call/Questionnaire Outcomes
Key themes arising from the Virtual Constellations:
Importance of rigorous gap analysis in agency planning processes
Optimization of operations, sustaining and enhancing satellite EO
Desire for increased participation from Chinese CEOS Members
Visibility that VCs bring within organizations
Resource constraints around best efforts engagement
Difficulty in connecting to the broader themes of CEOS
Challenges around travel and sustaining face-to-face engagement
Key statements from the Working Groups:
Motivated to integrate their agency assets in order that better decisions can be made more efficiently with EO, in particular by promoting collaboration in the development of systems.
Difficulty to get a broader connection between the membership and what is happening at the SIT and Plenary levels.
Proposal for CEOS leadership to participate in a WG meeting in order to provide an “external” point of view
WG members tend to be active within specific satellite projects in their agencies. Collaborations with other projects tends to distract from their primary efforts 1

7. Revisit of VC/WG Tangible Outcomes from SIT-33
April 2018
Conclusion from SIT-33 is that there is no ‘one size fits all’ for VCs and WGs, and that focusing on a common set of objectives and outcomes may be the best approach to go forward. 2

8. Questions from SIT-33 Virtual Constellations/Working Groups
How does CEOS best ensure continuity and sustainability of VCs/WGs?
What outputs are the VCs/WGs delivering? What additional outputs are needed or could they deliver?
What are the gaps within and between VCs that need to be addressed? How can they be addressed?
What obstacles to success or productivity are being raised by the VCs/WGs? And can they be resolved? If so, how?
Can, and how can the work of the VCs be mapped to future CEOS agency mission planning processes?
Can and how can, the work of the WGs support the VCs, as well as current and future CEOS Work Plan and GEO Work Programme items? 2

9. VC Health and Viability
SIT Assessment – SIT-33
Different approaches to the execution of each VC
P-VC activity beyond NASA-JAXA leads and meeting attendance is unknown
Meeting cadence and scheduling need to be deconflicted across VCs
*Table updated since SIT-33/2018 SIT TW

10. WG Health and Viability
SIT Assessment – SIT-33
WG health of leadership, contribution and engagement from CEOS Agencies, meeting processes, and active link to CEOS all are healthy
Identification of Vice Chairs sometimes an issue – all WGs currently have Chairs and Vice Chairs
All WGs demonstrate vibrant activity, participation, and contributions to the CEOS Work Plan
*Table updated since SIT-33/2018 SIT TW

11. SIT Chair-VC/WG/AHT/AHWG Tag-ups
July 2018

12. VC, WG, AHT Conversations
July Tag-ups – Virtual Constellations
How do VCs support and enable Agencies to make right decisions?
CEOS does not have a budget, agencies do
CEOS is looking for assessment and integration activities from VCs
Are CEOS leaders asking the right questions of the VCs?
Tenure for individual VC Co-leads – assess the feasibility of proposing a formal VC Co-Lead Rotation scenario
Could rotation of Co-leads increase buy-in from community and encourage engagement? Or create same recurring difficulties in identifying WG leadership?
Consistency of climate variables and consistency across measurements – key coordination opportunity for CEOS
CEOS as a data integrator, a topic now arising fresh within GEO Secretariat as well 1
To be discussed in agenda 6.7 – Ponder over lunch

13. VC, WG, AHT Conversations
July Tag-ups – Working Groups 1
Subsuming of AHTs to permanent WGs
FDA AHT and WGISS, for example
Expansion of scope of ARD to observations beyond land – where would ARD be best housed?
Agenda Item 5.4 and SITTW Action
Increased coordination with other external partners such as CGMS; WGCapD is interested in collaborating with CGMS because of maturity in capacity building activities
Agenda Item 6.2

14. Insights from VCs (and WGs and AHTs/AHWGs) at SIT VC/WG Working Day
September 2018 1

15. 2018 VC/WG Working Day
To provide an opportunity for the groups to discuss and identify areas of existing and potential collaboration, including all areas of CEOS activities – VCs, WGs, and AHTs.
Provide an opportunity to build better overall knowledge and understanding between VCs, WGs, and AHTs/AHWGs. The format and topics for this 5th VC/WG Day were discussed during the July tag-ups.
1/2/3
Session 1 - AM
Objectives and Introduction
Session 2 – Late AM/Early PM
Parallel Thematic Discussions
Session 3 - PM
Cross-Cutting Discussions and Conclusion
Introduction
1. Data
Main Points from Parallel Threads
Review of Topics for Thematic Parallel Groups
2. Climate
Discussion of Cross-Cutting Topics and Coordination
3. Oceans and Water Cycle
Conclusion
Session
Moderators
1. Data
Mirko Albani and Brian Killough
2. Climate
Jörg Schulz and Ben Veihelmann
3. Oceans and Water Cycle
Anne O’Carroll and Brad Doorn

16. Outcomes from 2018 VC/WG Working Day – Data
CEOS to be aware of developments in, and stay engaged with, the commercial sector
Emerging tools such as Google Datasets Search Tool
Increase communication on fundamental terms and definitions i.e., “ARD,” “Interoperability,” etc.
Improved connection to “top-down” CEOS objectives and deliverables, including tracking in CEOS Work Plan to ensure continued progress and Member support
Transition of AHT FDA activities into other CEOS entities
Tasks integrated into updated WGISS, LSI-VC, and activities
WGISS Technology Exploration Group must continue looking “over the horizon” for emerging trends
Include user perspective into WGISS, including collecting and communicating lessons learned
Update inventory of VC datasets and ensure discoverability/accessibility
Enhanced interactions with WGCV and WGCapD

17. Outcomes from 2018 VC/WG Working Day – Oceans and Water Cycle
Freshwater from Space Workshop Opportunity
Potential to combine VC/WG/AHT efforts focused on coastal research and observations
Consider developing a CEOS Coastal Strategy to enhance coordination across ocean elements and the land/ocean boundary
This idea will be considered as a part of the new CEOS Chair regional observing system activity
Potential to target specific projects (intersection of needs) in coastal and delta zones
Disasters (floods, harmful algal blooms, water quality impacts)
Aquaculture
Global Delta management
Direct need for in situ data access, potential for leveraging GEO activities
GEO Work Programme
Possibility for these activities to be included in the GEO Work Programme

18. Outcomes from 2018 VC/WG Working Day – Climate
Coordinated Action Plan with VCs and CEOS-CGMS WGClimate
Issue of prioritization of the implementation of actions to address GCOS needs vs. ECV Inventory Gap Analysis results
Next steps on GHG
Release GHG White Paper
Identify target specific actions to be assigned to CEOS bodies to be initiated
CEOS strategy need to define approach
Assessment of critical milestones identified in GHG White Paper (stocktake, prototype baseline products delivery…)
Addressed under Agenda Item 3.3

19. Outcomes from 2018 SIT Technical Workshop and Requests of Plenary3

20. Atmospheric Composition Virtual Constellation (AC-VC)
Co-Leads:
Jay Al-Saadi, NASA
Ben Veihelmann, ESA 3
AC-VC exists to sustain a systematic capability to provide essential observations of atmospheric composition from space. Key objectives include coordination of the collection and delivery of data to:
Develop and improve predictive capabilities for changes in the ozone layer
Monitor air quality
Monitor climate forcing associated with changes in atmospheric composition.

21. AC-VC Key Activities
AC-VC was commissioned to define the key characteristics of a global architecture for monitoring atmospheric CO2 and CH4 concentrations and their natural and anthropogenic fluxes from instruments on space-based platforms to reduce uncertainty of national emission inventory reporting and to track changes in the natural carbon cycle caused by human activities and climate change.
Over the course of the last 18 months, a dedicated team of researchers, space agency representatives, and scientists have created a White Paper, titled A Constellation Architecture for Monitoring Carbon Dioxide and Methane from Space
This White Paper proposes an architecture of a future greenhouse gas constellation designed to address the objectives outlined in the paper, and recommends a three-step plan to implement the architecture.
Discussed previously under Agenda Item 3.3
CEOS-CGMS Coordination on Greenhouse Gas Monitoring
Discussed previously under Agenda Item 3.6

22. Land Surface Imaging Virtual Constellation (LSI-VC)
Co-Leads:
Susanne Mecklenburg, ESA
Steve Labahn, USGS
Adam Lewis, GA
Welcome, Steve
Thank you, Jenn 3
The LSI-VC will focus on developing and implementing coordinated solutions across the following themes:
Promote analysis-ready data and minimizing the need for end users to understand satellite/pass/sensor-specific processing.
Draw together validated requirements identified by downstream land user communities
Encourage Moderate Resolution Interoperability (MRI) objective for complementarity and compatibility among the increasing number of Earth observing systems in the moderate resolution class for both optical and SAR sensors and the data received from them

23. LSI-VC Key Activities
LSI-VC has been incredibly successful in moving forward with the development of the CEOS Analysis Ready Data for Land (CARD4L).
Analysis ready data (ARD) is no longer a desire of global users, but is now becoming a requirement and an expectation and it is clear that space agencies need to make it easier for global users to get ARD.
Creation of the CEOS ARD website for three product family specifications – Surface Reflectance, Surface Temperature, and Radar Backscatter.
Discussed previously under Agenda Item 5.3
Outcomes from Joint LSI-VC/SDCG/GEOGLAM Meetings
Key overlaps between SDCG, GEOGLAM, and LSI-VC on CARD4L pilots and establishing links to user communities (for feedback, promotion, etc.) – priority areas for collaboration
Agreed a joint position on the continuity of the SDCG and GEOGLAM AHTs and the relation to LSI-VC going forward
Will be further discussed under Agenda Item 6.8

24. Ocean Colour Radiometry Virtual Constellation (OCR-VC)
Co-Leads:
Ewa Kwiatkowska, EUMETSAT
Craig Donlon, ESA 3
OCR-VC goal is to produce sustained data records of well-calibrated and validated satellite ocean colour datasets from measurements obtained from multiple satellites.
OCR-VC activities include calibration, validation, merging of satellite and in situ data, product generation, as well as development and demonstrations of new and improved applications.

25. OCR-VC Key Activities
OCR-VC is implementing the 2012 International Network for Sensor Inter- comparison and Uncertainty Assessment (INSIT-OCR) White Paper and focusing on coordinating cross-agency activities with respect to system vicarious calibration and collaboration on space instrument accuracy and stability to maximize the quality of OCR data records.
OCR-VC is working closely with the International Ocean-Colour Coordinating Group (IOCCG) and other calibration/validation leaders.
Linkages to CEOS Work Plan
Revision of OCR Essential Ocean Variables (observational requirements)
Lake Essential Climate Variables under development
Recommendations:
Stronger emphasis on aquatic biology, biogeochemistry, ecology and harmonization with ‘CEOS Strategy for Carbon Observations from Space’
Update WGClimate OCR ECV inventory to include missing datasets
COVERAGE to include variables beyond chlorophyll and increase spatial resolution

26. Ocean Surface Topography Virtual Constellation (OST-VC)
Co-Leads:
Remko Scharroo, EUMETSAT
Amaury Larue de Tournemine, CNES 3
OST-VC goal is to implement a sustained, systematic capability to observe the surface topography of global oceans from the basin scale to the mesoscale (~ 100 km). The surface topography from satellite altimeters and the upper-ocean density field from Argo profiling floats are oceanic analogues to the surface pressure from barometers and the density field from atmospheric profilers.

27. OST-VC Key Activities
OST-VC was successful in securing agency leadership to place Sentinel- 3A and -3B in tandem mission first as this is common to previous altimeter missions for long-term record.
This successful proposal is already paying off in detecting small inter- satellite processing differences.
OST-VC is also investigating how to link with other observables such as sea surface temperature and ocean color to determine surface topography
Altimetry, OST-VC, and CEOS: OST-VC links wider satellite altimetry community, Ocean Surface Topography Science Team, and CEOS
Inter-agency cooperation (bilateral/multilateral)
Jason-2/3: NASA, CNES, EUMETSAT, NOAA
SARAL: CNES, ISRO, EUMETSAT
Hy-2A: CNSA, CNES
Sentinel-3: EU, ESA, CNES
Sentinel-6: ESA, EU, EUMETSAT, NASA, NOAA and CNES
SWOT: NASA, CNES, CSA, UKSA

28. Current Constellation User Requirements Document (URD)
“Next 15 years of Altimetry”, 2009: Constellation User Requirement Assmanhausen OST-VC meeting
Objective 2018–2019: prepare a new URD
Discussed in OST-VC meetings 2016 and 2017
Early works through CNES phase 0 study (mix nadir/swath, global UR analysis)
What should be in it?
Analysis of user needs: systematic + exploratory
Swath altimetry + nadir altimetry: combined
Recommendation for an “operational constellation” (targets: Copernicus Next Gen, China altimetry programme)
Recommendation for additional science missions in complement
Multiple applications: mesoscale monitoring, polar oceans, long-term record for sea level rise
Links with other observables (e.g., SST, OC)

29. Ocean Surface Vector Wind Virtual Constellation (OSVW-VC)
Co-Leads:
Stefanie Linow, EUMETSAT
Rashmi Sharma, ISRO
Paul Chang, NOAA 3
OSVW-VC fosters the availability of best quality ocean surface vector wind data for applications in short, medium, and decadal time scales in the most efficient manner through international collaboration, scientific innovation, and rigor.

30. OSVW-VC Key Activities/ Mission Updates
Currently, the OSVW Constellation is mainly anchored by the scatterometer missions of EUMETSAT and ISRO, with a large number of upcoming Chinese scatterometer missions.
ASCAT (METOP-A&B)
Open and near real-time data access
METOP-C scheduled for a November 2018 launch
SCA (ASCAT Follow-On, EPS-SG, from ~2022 / 23)
ASCAT available through the EPS-SG/SCA launch
SCATSAT September 2017 (injected into ~9:45am local crossing time and drifting to ~8:45am)
Open and near real-time data access (since April 24, 2017)
OSCAT follow-on (OceanSat-3&3A) ~2018/2019
CMA will be providing OSVW measurements starting with FY-3E launch (late 2018)
NSOAS HY2 series: first tests to provide NRT data via EUMETCast, HY2B planned for launch in Oct 2018
CFOSAT (launch planned for Nov 2018), data distribution pending agreements
“Optimum (minimum) OSVW constellation is at least 3 scatterometers in orbits designed to roughly meet WMO requirements (observations every 6 hours); one instrument in a non-sun- synchronous orbit for sampling the diurnal cycle, better mid-latitude sampling and provide inter- calibration.”

31. Precipitation Virtual Constellation (P- VC)
Co-Leads:
Steve Neeck, NASA
Riko Oki, JAXA 3
P-VC goal is to establish an international framework to guide, facilitate, and coordinate the continued advancement of multi-satellite global precipitation measurement by
Facilitating implementation of the Global Precipitation Measurement (GPM) mission and encouraging more nations to contribute to the GPM constellation
Sustaining and enhancing an accurate and timely global precipitation data record including a Fundamental Climate Data Record fit for the purpose specified by GCOS for the monitoring of Precipitation as an ECV.

32. P-VC Key Activities 2018 ECV Gap Inventory Gap Analysis Report
P-VC is planning a response to recommendation #14*. An update will be provided by SIT-34.
NASA P-VC Leadership Transition
NASA is in the process of effecting a change in the P-VC Co- Chairmanship through standard CEOS practices.
Will be discussed under Agenda Item 6.7
*Recommendation #14: The CEOS Precipitation Virtual Constellation (P-VC) to further study the situation on precipitation climate data records taking into account the findings of WGClimate gap analysis report and to identify a way forward to stimulate the production of an improved precipitation CDR based upon the experiences gained with existing datasets. The P-VC should also consult with the CGMS-IPWG and WMO SCOPE-CM activity for the establishment of international collaboration for the development and production of such a CDR.

33. Sea Surface Temperature Virtual Constellation (SST-VC)
Co-Leads:
Anne O’Carroll, EUMETSAT
Ken Casey, NOAA 3
SST-VC serves as the bridge between the international SST community, Group on High Resolution SST (GHRSST), and the coalition of national space agencies, CEOS; provides a means for CEOS to present its needs and requirements to GHRSST and for GHRSST to present its needs directly to CEOS, the global community of space agencies.

34. SST-VC Key Activities
Significant progress has been made in the last year, organizing the community and advocating for Passive Microwave (PMW) continuity
SST-VC notes progress with two complementary missions that, if successfully put into operations, will fill the looming gap in PMW imagery.   
While not yet fully approved, the ESA Copernicus Imaging Microwave Radiometer (CIMR) will focus on low frequency/high resolution channels and would result in a step-change in EO capability with potential to revolutionize SST and sea ice monitoring from space.
Second area of progress is from JAXA on AMSR2 follow-on mission, AMSR3.  AMSR3 entered the pre-project phase in September. 
Both AMSR3 and CIMR have proposed launches in the timeframe.  The two missions are highly complementary and would provide unprecedented coverage and revisit of global ocean and high latitude sea ice conditions.
The SST-VC spent the last year focusing on a narrower number of activities specifically identified in the CEOS Work Plan: VC-2, VC-19, VC-35
Welcomed participation from CMA, KMA, NASA, and commitment from SANSA

35. Over the past year, the SIT Chair has had lots of engagement from the Virtual Constellations and the Working Groups.
Clear there is an exceptional level of commitment from the VC Co-Leads and WG Chairs and Vice Chairs.
Thank you to all the VC Co-Leads and WG Chairs and Vice Chairs for their thoughtful answers to the questionnaires and to the time spent preparing for and participating in the two sets of tag-up telecons and for the discussion and engagement at SIT-33 and 2018 SIT Technical Workshop and VC/WG Day.
Continue discussion in Agenda Items 6.7, 6.8, 6.9, and 6.10.