1. CEOS Water Strategy - Progress report to SIT 31 -
Committee on Earth Observation Satellites
CEOS Water Strategy - Progress report to SIT 31 -
Water Strategic Implementation Study Team
SIT-31 Agenda Item 7
CEOS Sstrategic Implementation Team
ESA/ESRIN, Frascati, Italy
19th-20th April 2016

2. Contents
1. WSIST Water Constellation FS
2. Progress
3. Way forward

3. CEOS Plenary Decision 29th CEOS Plenary, Nov 5-6, Kyoto decided;
CEOS Plenary endorsed the CEOS Response to the GEOSS Water Strategy Recommendations (CEOS Water Strategy) and a one year extension of the WSIST to implement the CEOS actions including the Water Constellation Feasibility.
CEOS Water Strategy

4. Proposed Major CEOS actions
CEOS takes the lead in addressing “Advancing satellite data acquisition”
C1: FS on Water Constellation
C2. C3 : participation in GEO water vapor and cloud activity
C4, C5: participation in the development of precipitation white paper
C6: coordinate LST missions toward improved ET estimation
C7, C8, C9 : CEOS agency activities already cover these.
C10: FS on hyperspectral satellite mission on water quality measurement
CEOS supports external activities, including:
E5: define soil texture map requirements and communicate them to IGWCO
E8: participate in GEO activities to define a global framework for surface water storage monitoring　

5. Water Constellation FS
GEO Water Strategy Recommendation C1:
The feasibility of developing a Water-Train satellite constellation should be assessed. This suite of satellites would be modelled after the A-Train, providing a space segment of an observation system that would capture all fluxes and stores of the water cycle using a diverse suite of platforms and instruments. This system would operate as a Virtual Water Cycle Constellation.
The A-Train

6. Water Constellation FS Progress
FS Work Plan was set and regular monthly telecons have been held.
Phase 1 (Jan to Mar 2016) was completed.
User requirements were reviewed and the GEO user requirements were found most comprehensive.
FS skeletons (requirements, capabilities, relevant CEOS missions, issues, synergies ) with 6 high priority parameters (precipitation, soil moisture, evapotranspiration, groundwater, river discharge and water storage) were studied.
A list of experts including WSIST members and invited FS participants was developed.
A synergy case of precipitation and soil moisture is being studied.
Phase 2 (April – June 2016) for gap analysis and gap filling measure study is starting.
Phase 1 (Jan-Mar)
Requirements study
Phase 2 (Apr-June)
Individual parameter study
Phase 3(July-Sep)
Synergistical obs study

7. FS Skelton FS Skelton for 6 parameters has been developed. Mission
coordination Gap
analysis
Requirements
Existing/
planned
capabilities
Identified
CEOS
missions
Synergy
with other
parameters

8. User Requirements
User requirements of GEO/IGWCO, WMO, GCOS were studied.
GEO/IGWCO requirements were found useful to start with.
Example of User requirements for precipitation
Variable
Horizontal
Resolution
Time
Vertical
Resolutio n
Accuracy
Latency
Precipitation
L:1km
R:10km
G:50 to 100 km to 500 km
Also stated variably as 5 km to 50 km etc.
L: 1hr
R:3hr
G:1d
Also stated variably as:0.08hr to 0.5hr; 1h to 12h, or 1d to 3d
N/A
0.1mm/5%
Also stated variably as: 0.1mm/h to 1mm/hr or 0.5mm/hr to 3mm/hr; 0.5mm/d to 5mm/d; 2mm/d to 10mm/d
0.1h to 6hr
3hr-24hr;1d- 2d;7d to 30d or RT and DT(App.Dep endent)
Source: GEO task US-09-01a: Critical Earth Observation Priorities

9. Existing/planned capabilities
Existing/planned capabilities were reviewed.
Current capabilities of precipitation observation
Product / Source
Horizontal
Resolution / Coverage
Time
Resolution
Vertical
Accuracy
Latency
CMORPH / NOAA CPC
8 km / 50°S-N
0.5 hr
N/A
18 hr
GSMaP-NRT / JAXA
0.10° lat/lon / 60°S-N
1 hr NA
0.2mm/hr
(GPM/DPR)
4 hr
IMERG / NASA
30 min
4 hr “early”; 12 hr “late”
NRL Real Time / NRL Monterey
0.25° lat/lon / 40°S-N
3 hr
PERSIANN-CCS / UC-Irvine
0.04° lat/lon / 60°S-N

10. Water Cycle observation status: requirements vs existing/future capabilities
Horizontal
Resolution
Time
Vertical
Accuracy
Latency
L:1km
R:10km
G:50 to 100 km
L: 1hr
R:3hr
G:1d
N/A
0.1mm/5%
0.1h to 6hr
Green: satisfied
yellow: marginal
red: not satisfied
Precipitation
Horizontal
Resolution
Time
Vertical
Accuracy
Latency
L:0.1km to 1km
R: 10km
G:50 to 100km
L/R: 1 to 6 hrs R:1d to 3d
G:1 to 30d to 3 months  
10cm Res. to 1m depth;
0.02m3/m3
NRT or 0.5d to 1d
Soil Moisture
Horizontal
Resolution
Time
Vertical
Accuracy
Latency
L:1km
R:10km
G:50 to 100km
L:1 to 6 hrs
R:1d
G:1d to 1m
Surface (E), and LS veg cover or canopy ht for ET
0.1mm or 5%. RT
Evaporation/ ET
Horizontal
Resolution
Time
Vertical
Accuracy
Latency
L/R:1km-10km
R/G:50km to 100km
1m to 3m to 1year
0.1km;Variable--depth
5%-7％(Depth to W-table)
1m to 3m Also stated as TBD-
Ground
Water
Run-off
Horizontal
Resolution
Time
Vertical
Accuracy
Latency
L:1km-10km G: 50 km-200km
L:1 to 6 hrs
R/G:1d-10d,
N/A
5%10%;Units:m**3/sec.
Hourly to daily (NRT)
Horizontal
Resolution
Time
Vertical
Accuracy
Latency
L/R:1km-40km
G:50km to 100km
1wk to 1m
Or 30d to 90d
N/A
10cm-20cm(level);Or 5%.
L/R: 1w-1m R/G: 30d to 90d
Surface Water
Storage

11. Relevant CEOS Missions
Relevant CEOS missions for the 6 parameters were identified.
Precipitation DMSP F15 SSMI [limited]; DMSP F16, F17, F18, and F19 SSMIS; GCOM-W1 AMSR2; GPM GMI) and microwave sounders (NOAA-18, NOAA-19, Metop-A, and Metop-B MHS; Megha-Tropiques SAPHIR; SNPP ATMS)
Soil moisture
SMOS, SMAP, AMSR-E/2, Windsat, FY-3/MWRI, GPM/GMI
Active – Aquarius, RADARSAT, ASCAT, SAOCOM, Sentinel-1A
Evapotranspiration - GEO, MODIS, LANDSAT, VIIRS?
Ground water - GRACE-II
River discharge – SWOT
Water storage
TBD

12. Mission Coordination
CEOS mission coordination is studied based upon gap analysis of requirements/capabilities.
Precipitation - GCOM-W/AMSR2 follow-on mission
- GPM follow-on mission
- Access to Chnese and Russian microwave radiometer data
Soil moisture
- SMAP and SMOS follow-on missions
- AMSR2 follow-on
- WCOM of Chinese Academy of Science?
Evapotranspiration - No issue and no coordination is required.
Ground water - No issue
River discharge - No issue
Water storage
- Inclusion of snow/ice in the surface storage is an issue to be addressed.

13. Expert list
An expert list has been developed. Voluntary contribution to the FS is very much apprecaited.
No,
Parameter
Expert 1
Precipitation
Ralph Ferraro(NOAA)
Bob Kuligowski(NOAA) 2
Evaporation/ET
Selma Cherchali(CNES)
Xiwu Zhan(NOAA) 3
Soil moisture 4
Run off
John W. Jones (USGS) 5
Ground water
 TBD 6
Surface water 7
Overall
Toshio Koike
Richard Lawford

14. Synergistical Observation Study
Synergistical observaiton study among the 6 parameters is being
considered.
As initial step, a case study of precitipitationand soil moisutre is
being made.
In additon to individual requirements, synergistical observation
requirements for precipitation and soil moisture will be considered.

15. Integrated Water Observation System
Source:
4th telecon
by Prof. Koike

16. No major issues, but a lot to be done
Scoping and method of FS are to be established.
Need agreement on requirement source to be used.
Synergistical observation requirements among 6 parameters need to be defined.
Interaction with similar parallel activities, such as post-GPM study,Decadal Survey Mission study and GEO Initiatives
Engineering analysis of technical feasibilities will be needed.

17. Outcomes of the side meeting
The side meeting of April 18 was very useful with guidance and feedbacks from CEOS members and participants;
For requirements, we need to check consistency with GCOS ECV reqirements and may need to reflect GEO's new SBA requirement consolidation process. We also need to inform GEO of our FS activities.
For experts, we welcome any voluntary experts, such as those of run-off and surface water storage. We also need ground water expert(s).
For cost-benefit analysis, we may not need to conduct detailed analysis until we identify practical candidate missions. Rather we need strong case to justify the FS.
For requirement, we need to consider political requirements, such as COP21 and SDGs. In this context, we need to make linkage with the GEMI water observation system initiative for SDGs within UN (FAO and UNEP)

18. SIT is Requested to
acknowledge steady progress of the FS and provide any guidance and advice on the FS approach.
encourage water experts of CEOS agencies to support the FS
encourage engineering anlysis support of CEOS agencies for the FS later.

19. Way Forward
Gap analysis for the 6 parameters and synthesis study to integrate the gap analysis findings and propose CEOS mission scenario will be made.
Phase 2 (April 2016 to June 2016)
Gap analysis by water experts for each parameter
Propose gap filling measures
Phase 3 (July to Sep 2016)
Synthesize proposed gap filling for six priority parameters
Propose integrated gap filling and mission scenario for disaster-energy- agriculture annex

20. Appendix

21. Water Constellation Study memebers
CEOS Water Strategy Implementation Study Team (WSIST) members
Bojan Bojkov (WGCV/ESA)
Selma Cherchali (CNES)
Jared Entin (NASA)
Ralph Ferraro (NOAA)
Bob Kuligowski (NOAA)
Kerry Sawyer (NOAA)　
John W. Jones (USGS)
Marie-Josee.Bourassa (CEO/CSA)
Arnold Dekker (CSIRO)
Jono Ross (DCEO/GA)
Chu Ishida (JAXA)
Water Constellation FS experts
Rick Lawford
Toshio Koike (U.Tokyo)
Xiwu Zhan(NOAA)
Great contribtuion of the WSIST members and FS experts are very much appreciated !