Hosted by:

1
Welcome to the inaugural meeting of the WATER HM
Science Working Group

• Hosted by
• Doug Alsdorf, Ohio State
• Lee-Lueng Fu, JPL
• Nelly Mognard, LEGOS-CNES
• Yves Menard, LEGOS-CNES

SWG Goal To formulate the missions science goals
and requirements and to conduct a mission
definition study leading to an optimal
preliminary design of the mission given science
requirements and technology and cost constraints.
Meeting Goal To make decisions and initiate
actions that will eventually complete the overall
goal of the SWG. By the end of the meeting,
October 30th, decisions will be made on the
issues described in the agenda.
Funding from CNES, NASA, JPL, and Ohio State
University
2
Meeting Conclusion

• Are the science questions articulated and
  prioritized?
• Are the risk reduction studies aligned with the
  science questions and prioritized?
• Are funding sources identifiable for these
  trade-off studies?
• Are the team leaders identified?
• Do we have a timeline?

This is not an informational or science
presentation meeting like AGU. This is a meeting
where ideas will be presented and decisions made,
thus keeping WATER HM moving forward. Feel free
to share your ideas and thoughts.
3
Monday Morning
By the end of the morning session we will define
and prioritize the science questions.
830 - 840  Introduction, Accomplishments of
WATER HM this past year Doug Alsdorf  840 -
850 The Science Working group Charge Lee
Fu 850 - 915 Updates from CNES and NASA
HQ Eric Lindstrom, Eric Thouvenot, Herve
Jeanjean, Jared Entin, Mike Freilich 915 -
930  Review of Hydrology Science
Questions Dennis Lettenmaier 930 - 945
Review of Oceanography Science Questions Lee
Fu 945 - 1115 Break-Out Session on Science
Questions 1115 - 1130 Coffee Break 1130 -
1230 SWG Consensus on Science
Questions moderated by Doug Alsdorf, Lee Fu,
Nelly Mognard, Yves Menard 1230 - 130 Lunch
4
Monday Afternoon
The afternoon session is focused on science
drivers to mission design and technology.
130 - 140 Introduction to Risk Reduction
Issues Doug Alsdorf 140 - 210 Hydrology
virtual mission Dennis Lettenmaier 210 - 345
Spacecraft Power and Orbit, 15 minute
presentations Tidal aliasing issues Richard
Ray Tidal aliasing issues Florent
Lyard Current orbit design Steve
Nerem Spacecraft and associated key points
Bruno Lazard JPL studies Ernesto Rodriguez 345
- 400 Coffee Break 400 - 500 Water vapor
corrections and radiometer issues, 15 minute
presentations Issues with coastal zones Ted
Strub Options with various radiometers Shannon
Brown CLS perspective on radiometers Estelle
Obligis 500 - 515 First day meeting
wrap-up Doug Alsdorf
5
Tuesday Morning
The first morning session is focused on
prioritizing the risk reduction studies.
830 - 850 Field results of Ka-band radar over
rivers, Delwyn Moller 850 - 915 Ka-band radar
studies, CNES Pre-Phase A work, Bruno Cugny 915
- 1015 Entire Group, Discussion and finalize
risk reduction studies, issues of rain rates and
Ka-band vs. Ku-band will be raised, Moderated by
Doug Alsdorf, Lee-Lueng Fu, Nelly Mognard, Yves
Menard 1015 - 1030 Coffee Break 1030 - 1100
Timeline for completion of SWG Goals and related
report Discussion will focus on report content,
assignments, and schedules. People will be named
to lead risk reduction studies. Moderated by
Lee-Lueng Fu 1100 - 1130 Mission timelines
and funding availability Discussion will focus
on a potential schedule that includes submission
of SWG report in 2008, pre-project planning in
2009, and project start in 2010. NASA HQ and
CNES will need to comment on the reality of this
scenario and corresponding funding issues.
Timeline will be finalized. Eric Lindstrom, Eric
Thouvenot, Herve Jeanjean, Jared Entin, 1130 -
1200 Open Forum What are the issues on the
horizon? How will we handle the massive data
volume from WATER HM? To what degree and how
should the SWG connect with society and policy?
Should we engage international agencies? To what
degree and how should the SWG connect with
operational applications/operational agencies?
Moderated by Doug Alsdorf, Lee-Lueng Fu, Nelly
Mognard, Yves Menard 1200 - 1215 Meeting
wrap-up Doug Alsdorf
6
WATER HM Accomplishments this past year

• AGU Special Session
• December 2006
• Selected by the NRC Decadal Survey
• January 2007
• Publication of EOS and Reviews of Geophysics
  articles
• June 2007
• Mission featured in Columbus Dispatch
• June 2007
• Formation of the Science Working Group
• Result of letters of agreement exchanged between
  NASA HQ and CNES
• August 2007
• Ocean Sciences ASLO Special Session
• March 2008
• Additional Accomplishments
• Various meetings during the year, e.g., Charles
  Elachi, JPL Mike Freilich NASA HQ
• Interactive WATER HM web page with new
  participants added regularly

7
Charge to Oceanography and Hydrology Break-Out
Groups

• Identify science questions and prioritize them
• Is this the list of questions that you think are
  most appropriate for WATER HM? Is the priority
  ordering correct? Do you suggest modifications? 
• Note that we are prioritizing only within the
  hydrology or only within the oceanography
  category.
• We should have one key, overarching science
  question for oceanography and similarly one for
  hydrology.  Hopefully, these questions will be
  nearly self-evident regarding their importance. 
• A goal of the break-out session is to
  word-for-word identify the respective key science
  question.
• Because WATER HM is a wide-swath altimeter, the
  questions should focus on the measurements
  collected from KaRIN.
• Hydrology Science Questions Might Include
• What is the spatial and temporal variability in
  the world's terrestrial surface water storage and
  how can we predict these variations more
  accurately?
• How much water is stored on a floodplain and
  subsequently exchanged with its main channel?
• What are the policy implications that freely
  available water storage data would have for water
  management?
• How much carbon is potentially released from
  inundated areas?
• Can health issues related to waterborne diseases
  be predicted through better mappings?
• Oceanography Questions Might Include
• What is the small-scale variability of ocean
  surface topography that determines the velocity
  of ocean currents? How are fronts and eddies
  formed and evolving? How is oceanic kinetic
  energy dissipated?
• What is the synoptic variability of coastal
  currents? How do the coastal currents interact
  with the open ocean variability? What are the
  effects of coastal currents on marine life,
  ecosystems, waste disposal, and transportation?
• How does a hurricane interact with the
  small-scale variability of the upper ocean heat
  storage? What is the ocean's dynamic response to
  hurricanes?  How is the new knowledge to be used
  to improve hurricane forecast?

8
SWG Consensus on Science Questions
Decisions 1 2

• Identify science questions and prioritize them
• Potential other science targets (bathymetry, land
  topography, etc.) should be identified, but only
  those that avoid science, technology, and cost
  creep.
• e.g., sea-ice could be a target but probably
  should not drive the orbit selection.
• The science drivers should be prioritized in
  terms of ?critical and must have? to those of
  less importance but still valuable. This
  prioritization should focus the mission and
  prohibit creep.
• e.g., measuring surface water storage changes is
  critical whereas measuring sea ice freeboard is
  not.
• Questions need careful articulation and accuracy
  in their wording.
• e.g., how much surface water vs. what is the
  spatial and temporal variability in surface
  water
• Technology and Mission Considerations
• Mission lifetime is 3 to 5 years, with increasing
  costs for longer times. Science questions should
  be answerable with data collected during mission
  timeframe.
• Questions should be answerable by the accuracy
  and resolutions provided by KaRIN.
• Additional Considerations
• Modeling is increasingly important for
  understanding the global water cycle and oceanic
  circulation issues. What do models require?

9
Introduction to Risk Reduction Issues

• Spacecraft power and orbit
• Sun-Synch smaller, non-rotating solar panels
• non-SS articulated solar panels, batteries
• Issues lead to mass requirements, which drive
  launch vehicle and platform selection
• Essentially, the orbit is the key issue
• Hydrology Virtual Missions identifying needed
  spatial and temporal resolutions
• Spatial resolutions lt100 m, but how much smaller?
• Temporal sampling is not strictly limited
• Order of magnitude difference in down-linked data
  amounts when comparing 2x30 m and 16x50 m pixels
• Radiometer accuracies over coastal and land
  surfaces and alternative strategies
• What is the method for removing water vapor
  errors?
• Field results of Ka-band radar over rivers
  (Tuesday Morning)
• Ka-band does produce off-nadir reflections over
  rivers.
• Mitigation of rain rates (Tuesday group
  discussion)
• Ka vs. Ku band discussion

10
SWG Consensus on Risk Reduction Studies
Decisions 3 4

• Identify mission risks and studies to mitigate
  these
• Our science questions need to drive the
  technology. For example, oceanographic science
  questions define the need for certain orbits
  whereas hydrologic science requires high-spatial
  resolutions to sample rivers with smaller widths
  (less than 100m).
• This sampling may require a certain amount of
  power to ensure a signal-to-noise ratio capable
  of supplying the needed height accuracies. Power
  requirements are a function of the orbit.
• CNES developed initial studies necessary for
  submitting the WatER proposal to ESA whereas JPL
  has a large investment in WSOA related studies.
  The SWG needs to update these previous studies by
  ensuring that the hydrology and oceanographic
  science drivers are within a reasonable budget
  (i.e., develop cost trade-offs).
• Prioritize Risk Reduction Studies
• Various studies have been discussed such as a
  need to update the CNES WatER power consumption
  study which focused on sun-synchronous orbits
  with stationary solar panels instead of a
  non-sun-synchronous orbit with solar panels
  rotating once per orbit (or other
  configurations).
• Additional needed studies might include
• the usage of DEMs to mitigate spacecraft roll
  errors and to correct errors from atmospheric
  water vapor
• determining the power necessary to meet the
  required height accuracies
• the degree to which rain rates are mitigated
• height accuracy over small rivers
• Prioritizing the needed studies and securing
  their funding are functions of the SWG.
• The SWG will facilitate the organization and
  cooperation of these studies, especially as WATER
  HM heads toward implementation of Phase A. A key
  issue is to integrate these studies so that
  spatial, temporal, and height accuracies implied
  by the science studies are fit into the
  technology studies to determine related costs.

11
Team Leaders and Action Items
Decisions 5 6

• Leadership of Risk Reduction Studies
• People in the SWG were selected for their
  expertise related to the issues outlined in
  Decisions 1-4. We expect that individuals from
  the SWG will lead the risk reduction studies and
  provide final reports upon conclusion of the
  studies. A key aspect of leading a risk-reduction
  team is to ensure that the optimal number of
  researchers are immediately available to conduct
  the work.
• Timeline
• A timeline is needed to ensure that the mission
  makes steady forward progress and so that CNES
  and NASA can make plans for funding key
  activities. A job of the SWG is to ensure timely
  funding for these trade-off studies.
• Action Item 1, Ensure funding sources
• Post-meeting actions will immediately focus on
  securing funds for the highest priority
  risk-reduction studies. NASA, JPL, and CNES have
  all indicated willingness to engage in funding
  key studies.
• Action Item 2, Communicate with team leaders
• We need to develop a routine of regular
  interaction with risk-reduction teams. Telecoms
  will be used as well as the WATER HM web page
  http//bprc.osu.edu/water/ for archiving
  preliminary and final study results, providing
  links to risk-reduction models.
• Action Item 3, Continue to develop joint science
  community
• A key aspect of the SWG is to ensure that the
  global community of oceanographers and
  hydrologists recognize the importance of bringing
  together our two communities. This will likely
  require regular WATER HM presentations at
  international and specialized meetings,
  occasional open meetings hosted by the SWG,
  publication of results, and interactions with key
  leaders at CNES and NASA HQ (and perhaps other
  Federal and National agencies?).

12
Meeting Conclusion

• Open Forum
• What are the issues on the horizon?
• How will we handle the massive data volume from
  WATER HM?
• To what degree and how should the SWG connect
  with society and policy?
• Should we engage international agencies?
• To what degree and how should the SWG connect
  with operational applications/operational
  agencies?
• Are the science questions articulated and
  prioritized?
• Are the risk reduction studies aligned with the
  science questions and prioritized?
• Are funding sources identifiable for these
  trade-off studies?
• Are the team leaders identified?
• Do we have a timeline?