The NASA Soil Moisture Active Passive (SMAP) Mission will provide global observations of soil moisture and freeze/thaw state from space. We outline how priority applications contributed to the SMAP mission measurement requirements and how the SMAP mission plans to foster applications and applied science

Entekhabi, Dara

Kellogg, Kent H.

Moran, M. Susan

Njoku, Eni G.

O'Neill, Peggy E.

NASA Technical Reports Server

FOSTERING APPLICATIONS OPPORTUNITIES FOR THE NASA 
SOIL MOISTURE ACTIVE PASSIVE (SMAP) MISSION 
 
M. Susan Moran(1), Peggy E. O’Neill(2), Dara Entekhabi(3), Eni G. Njoku(4) and Kent H. Kellogg(4) 
 
(1) USDA/ARS Southwest Watershed Research Center, Tucson, AZ 85719, susan.moran@ars.usda.gov   
(2) Hydrological Sciences Branch, NASA Goddard Space Flight Center, Greenbelt, MD 20771  
(3) Massachusetts Institute of Technology, Cambridge, MA  02139  
(4) NASA Jet Propulsion Laboratory, Pasadena, CA  91109 
 
 
ABSTRACT 
 
The NASA Soil Moisture Active Passive (SMAP) Mission 
will provide global observations of soil moisture and 
freeze/thaw state from space.  We outline how priority 
applications contributed to the SMAP mission 
measurement requirements and how the SMAP mission 
plans to foster applications and applied science. 
 
Index Terms— Soil moisture, freeze/thaw, applied 
science, Earth land surface 
 
1. INTRODUCTION 
 
The Soil Moisture Active Passive (SMAP) Mission is 
one of the first Earth observation satellites being 
developed by NASA in response to the National 
Research Council’s (NRC’s) Decadal Survey, Earth 
Science and Applications from Space: National 
Imperatives for the Next Decade and Beyond [1]. 
SMAP will make global measurements of the soil 
moisture present at the Earth's land surface and will 
distinguish frozen from thawed land surfaces [2].  
Direct observations of soil moisture and freeze/thaw 
state from space will allow significantly improved 
estimates of water, energy and carbon transfers 
between the land and atmosphere.   
 
In this paper we outline how applications and applied 
science were developed for SMAP and how the science 
drivers and priority applications contributed to the 
overall mission measurement requirements. The 
requirements are diverse and convergence on a common 
set of values entailed some challenges. Nevertheless the 
way forward was found and the challenge for the 
mission now is how to foster and engage the 
applications community.  The project has formed a 
SMAP Applications Working Group which now has 
over 150 members (see 
http://smap.jpl.nasa.gov/science/applicWG). This paper 
concludes with a plan for fostering applications through 
engagement with the applications community. 
 
2. DERIVATION OF MEASUREMENT 
REQUIREMENTS 
 
The Decadal Survey was composed of six disciplinary 
panels.  Five of the six panels cited applications and 
applied science uses for SMAP data (Table 1).  The 
broad and multi-disciplinary call for soil moisture and 
freeze/thaw data resulted in the placing of SMAP in the 
first tier of priority Earth science missions. An equally 
important factor was the maturity and technological 
readiness of SMAP due to its heritage in the cancelled 
Hydros Earth System Science Pathfinder mission. 
 
The SMAP Science Definition Team (SDT) defined 
five major science goals for driving the mission 
measurement requirements: 1) Estimation of global 
water and energy fluxes at the land surface; 2)  Extend 
weather forecast skill; 3) Develop flood and drought 
predictions; 4) Quantify net carbon flux in boreal 
landscapes; and 5) Link terrestrial water, energy and 
carbon cycle processes.  Alongside these science drivers 
there are applications that should also be major 
components of the mission. The SMAP SDT derived a 
set of common measurement requirements based on the 
driving science and the priority application goals for the 
project. 
 
https://ntrs.nasa.gov/search.jsp?R=20110011771 2019-08-30T15:46:48+00:00Z
The SMAP SDT next attempted to identify the spatial 
scales, data refresh and accuracy requirements 
associated with each general area of application in 
Table 1. For each application-area, the specific 
decision-support systems or models that are used to 
support them were identified (second column of Table 
2).   
 
Table 1: NRC Decadal Survey Panel Citation of SMAP Applications. 
 
Table 2: Summary of Soil Moisture Information Requirement. 
Topic Application Model Soil Moisture Requirement 
Weather Initialization of Numerical Weather Prediction (NWP) Hydrometeorology 
Climate 
Boundary/Initial Conditions for Seasonal Prediction Hydroclimatology 
Testing Land Surface Models in Climate Models Hydroclimateology 
Drought and 
Agriculture 
Seasonal Precipitation Prediction Hydroclimatology 
Regional Drought Monitoring Hydroclimatology 
Crop Outlook  Hydroclimatology 
Floods 
River Forecast Model Initialization Hydrometeorology 
Flash Flood Guidance (FFG) Hydrometeorology 
NWP Initialization for Precipitation Forecast Hydrometeorology 
Human Health 
Seasonal Heat Stress Outlook Hydroclimatology 
Near-Term Air Temperature and Heat Stress Forecast Hydrometeorology 
Disease Vector Seasonal Outlook Hydroclimatology 
Disease Vector Near-Term Forecast Hydrometeorology 
Decadal Survey Panels Cited SMAP Applications 
Water Resources and 
Hydrological Cycle 
1. Floods and Drought Forecasts 
2. Available Water Resources Assessment 
3. Link Terrestrial Water, Energy and Carbon Cycles 
Climate Variability and Change 4. Longer-Term and More Reliable Atmospheric Forecasts 
Weather Science and 
Applications 5. Longer-Term and More Reliable Atmospheric Forecasts  
Human Health and Security 6. Heat Stress and Drought 7. Vector-Borne and Water-Borne Infectious Disease 
Land-Use, Ecosystems, and 
Biodiversity  
8. Ecosystem Response (Variability and Change) 
9. Agricultural and Ecosystem Productivity 
10. Wild-Fires 
11. Mineral Dust Production 
Then the data attributes (resolution, revisit, and 
accuracy) were assembled for each application. These 
requirements were subsequently grouped under either 
Hydrometeorology or Hydroclimatology to make the 
problem tractable. Each grouping (Hydrometerology 
and Hydroclimatology) has its own resolution 
requirement, but they share revisit and accuracy 
requirements (Table 3).  Separately, there is a Carbon 
cycle requirement that drives the freeze/thaw 
classification uses for the data.  Finally, a baseline 
mission set of measurement requirements (last two 
columns in Table 3) were derived as a recommendation 
for the mission design.  
 
Table 3: Soil Moisture Measurement Requirement. 
Requirement Hydro-Meteorology 
Hydro-
Climatology Carbon Cycle 
Baseline Mission 
Soil 
Moisture 
Freeze/ 
Thaw 
Resolution 4–15 km 50–100 km 1–10 km 10 km 3 km 
Revisit 2–3 days 3–4 days 2–3 days  3 days 2 days 
(>45N) 
Accuracy 4–6%  Error 
(1σ) 
4–6% Error 80–70% Accuracy 
(Binary 
Classification) 
4% Error 80% 
Accuracy 
 
 
 
 
3. FOSTERING THE APPLICATIONS 
 
A key challenge for the SMAP project is to foster 
applications and applied science given: 1) the limited 
budget, 2) long development horizons, and 3) the 
primacy of science over applications in driving 
measurement requirements for NASA-funded projects.  
We do not believe that science and applications are 
competing with one another as much as they used to.  
Advances in computation and data transfer, the 
maturation of applications, and the increased emphasis 
of Earth scientists on transferring their discoveries to 
applications expediently has led to significant overlaps 
between science- and application-derived requirements 
for data.  The SMAP project is working with the 
SMAP Applications Working Group to expand this 
area of overlap and develop data products that bring 
significant value to applications. 
 
For this purpose, the SMAP Project sponsored the first 
in a series of workshops on the topic.  During 9-10 
September 2009, an open meeting with 125 persons in 
attendance was held at NOAA Silver Spring, MD 
(http://smap.jpl.nasa.gov/science/applicWG/).  This 
meeting formed the basis for the SMAP Applications 
Plan. 
 
The SMAP Applications Workshop produced the 
following tangible results: 
1. The first detailed summary of SMAP 
applications; 
2. A compilation of SMAP practicing and 
potential end-users, including early adopters; 
3. A review of the broad science community that 
can build support for SMAP applications; 
4. Dozens of contacts that should be made in the 
short-term; and 
5. Prioritization of SMAP Applications Plan 
implementation tasks, where high priority items 
include hiring a SMAP Applications 
Coordinator and implementing the process to 
determine and engage SMAP Early-Adopters. 
 Following the meeting, a set of mutual expectations 
between the SMAP project and the SMAP Applications 
Working Group was developed.  For the SMAP 
Applications Working Group, the Mission plans to: 
1. Implement open access to planned SMAP data 
products; 
2. Make available SMAP products with moderate 
latencies of 12 and 24 hours [the SMAP 
project will make a best effort to reduce these 
latencies]; 
3. Establish a Community of Early-Adopters; 
4. Steer end-users to NASA Applied Sciences 
Program (ASP) solicitations with potential 
opportunities for SMAP product application; 
5. Engage end-users in SMAP pre- and post-
launch cal/val activities; 
6. Create access to simulated SMAP data 
products generated pre-launch by algorithm 
and observing system simulation experiments; 
and 
7. Use the SMAP testbed to develop value-added 
products in the simulation environment for 
general distribution. 
 
In turn, the Mission expects the SMAP Applications 
Working Group to: 
1. Partner with SMAP SDT members; 
2. Communicate with the SMAP Applications 
Coordinator; 
3. Conduct preliminary scientific research to 
promote use of SMAP products; 
4. Refine our current understanding of SMAP 
products; 
5. Feed information back to the SMAP Mission; 
and 
6. Participate in SMAP calibration and validation 
activities. 
 
 
These mutual expectations form the basis for the 
engagement between the SMAP project and the 
applications community.  A 2nd Applications Workshop 
is planned for 2011 to be held at the location of a to-be-
determined SMAP Early Adopter.    In preparation, the 
SMAP SDT is working with the Community of 
Support to include more international applications and 
working with the NASA Applied Sciences Program to 
determine performance metrics to list in the SMAP 
Applications Plan.   
Coordination of applications needs with other Decadal 
Survey Missions was discussed at the 1st SMAP 
Applications Workshop.  The questions that arose 
included:  Is it possible to develop Applications 
Readiness Levels (ARL) across missions?  If so, how 
would NASA Headquarters implement ARL to take 
advantage of Mission products from Day 1?  
Alternatively, will NASA Headquarters develop metrics 
for applications success across all Decadal Survey 
Missions?  These unanswered questions should 
stimulate a multi-Mission dialogue led by the NASA 
Applied Sciences Program.   
 
4. REFERENCES 
 
 [1] National Research Council (NRC), “Earth Science 
and Applications from Space: National Imperatives for 
the Next Decade and Beyond”, available at 
http://www.nap.edu, National Academies Press, 400 
pages, 2007. 
[2] Entekhabi, D., E.G. Njoku, P.E. O’Neill, K.H. 
Kellogg, W.T. Crow, W.N. Edelstein, J.K. Entin, S.D. 
Goodman, T.J. Jackson, J. Johnson, J. Kimball, J.R. 
Piepmeier, R.D. Koster, K.C. McDonald, M. 
Moghaddam, M.S. Moran, R. Reichle, J.C. Shi, M.W. 
Spencer, S.W. Thurman, L. Tsang and J. van Zyl, 
“The Soil Moisture Active and Passive (SMAP) 
Mission”, Proceedings of the IEEE, vol. 98, pp. 704-
716, May 2010. 
 


Fostering Application Opportunites for the NASA Soil Moisture Active Passive (SMAP) Mission

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server