1. Soil Moisture Active Passive
(SMAP) Calibration and Validation
Plan and Current Activities
T. J. Jackson, M. Cosh, R. Bindlish, W. Crow, USDA ARS HRSL
A. Colliander, E. Njoku, K. McDonald; NASA JPL
J. S. Kimball; University of Montana
S. Belair; Environment Canada
J. Walker, R. Panciera; University of Melbourne
P. O'Neill; NASA GSFC
July 29, 2010

2. Outline
• General aspects of the SMAP Cal/Val Plan
– Objectives
– Timeline
– Pre-launch vs. post-launch validation activities
• Ground-based (In Situ) validation
– Core Validation Sites
• Field experiments
– CanEx SM 2010

3. SMAP Cal/Val Objective
Approach
• A Cal/Val Plan is a SMAP mission requirement.
– Objective: calibrate and validate Level 1 through
Level 4 algorithms and products relative to the
mission requirements.
– Mission requirements include quantitative
specifications of accuracy associated with each
mission product
• Example: Provide estimates of the 0-5 cm soil moisture
with an accuracy of 0.04 m3/m3 at a resolution of 10 km.

4. SMAP Cal/Val Timeline
L1C_TB
Must reach a conclusion by
this point.
• Current plans are for SMAP to complete an In-Orbit Checkout
(IOC) period within 60 days after launchbeing ready and
Demands
• Following the IOC period, the SMAP Project will complete an
timely delivery of
validation data.
initial Cal/Val of the data products (6 months for Level 1
products and 12 months for Levels 2, 3, and 4).
• Cal/Val will continue throughout the mission to monitor
performance and assist in the improvement of algorithms.
Level 2/3/4
2/3/4
2/3/4

5. SMAP Cal/Val: Pre-launch vs. Post-launch
Approach
On-ground Ancillary data,
SDS calibration data,
in-orbit calibration
masks, external
model outputs,
• Pre-launch Cal/Val is focused on
data, etc, etc.
L1 L3,L4
validating that there are means in place
Instru Geophys.
Instrument
ment
counts
calibration
TB, σ0
param.
retrieval
SM (sf+rz),
F/T, NEE
to fulfill the mission objectives. In
particular
– ATBD identified activities that will
Pre-launch Cal/Val Activities improve algorithms and products.
– Establish infrastructure necessary for
SDS On-ground Ancillary data, post-launch Cal/Val.
calibration data, masks, external
in-orbit calibration model outputs,
data, etc, etc. • Post-launch Cal/Val is focused on
Instru
ment
Instrument
calibration
L1 Geophys.
param.
L3,L4
SM (sf+rz),
validating that the science products
counts TB, σ0 retrieval F/T, NEE
meet their quantified requirements, and
Feedback
Feedback
on improving the algorithms and
Post-launch Cal/Val Activities
quality of products over the mission
life.
(schematic diagram of data processing flow; SDS = Science Data System)

6. SMAP Cal/Val: Post-launch Resources
Approach
• Ground-based (in situ, tower, and aircraft)
• Products from other satellites
• Model products

7. SMAP Cal/Val: Pre-launch
Approach
• ATBD identified activities • Algorithm testbed
that will improve • Satellite products
algorithms and products – AMSR-E, SMOS, Aquarius
• Field campaigns
– Past
• SGP, SMEX….
• SMAPVEX08 Bindlish, Misra
– Ongoing
• Canadian campaign (CanEx)
• Australia campaign (SMAPEx) Walker
• San Joaquin Valley experiment
– Future
• Establish infrastructure • In situ sensor testbed Cosh
necessary for post-launch • Scaling methodologies
Cal/Val • Tower and aircraft SMAP simulators
• Core validation sites/collaboration

8. SMAP Ground-Based Validation
• SMAP will rely on in situ observations as one of
the tools used to validate the L2, L3, and L4
products.
– The logistics and costs require that we exploit
partnerships to the maximum extent.
– These must be ready to go before launch.
– What infrastructure do we need to establish now?

9. SMAP Ground-Based Validation
• Existing networks are a key resource/partner in SMAP
validation (No cost, mostly real time, and public
domain).
– These are typically sparse…scaling is the key issue.
– Standards and compatibility are also concerns.
• Dense networks with nested scales are needed: Core
Validation Sites (CVS).
– Some exist but more are needed.
– These should meet some criteria that will facilitate SMAP
product validation.
– Some form of agreement establishing collaboration with the
SMAP project.

10. SMAP Cal/Val SM Core Validation Sites
• Basic science requirements (suggestions!)
– Represent the 10 km product area
• Also consider providing 40 km and 3 km scales
– Provide the equivalent of volumetric soil moisture obtained
using the gravimetric method (Calibrated)
• Establish that it provides a measure of the 0-5 cm layer
• Also consider providing the 0-100 cm layer
– Multiple sampling locations within the site that can be used
to accurately estimate the product grid average
• Statistical confidence must be established
– Supporting meteorological instrumentation
– Supporting ancillary data sets such as soils, land use, and
vegetation biomass

11. Example of a SMAP Soil Moisture Core
Validation Site (J. Walker Univ. Monash)
Augmenting an
existing radiometer
scale network to
support SMAP
SMAP Radiometer Pixel – 34x38km
SMAP Radar pixels ~ 3x3km
SMAP joint radiometer/radar soil
moisture – 9x9km
Existing stations
New stations

12. SMAP Cal/Val SM Core Validation Sites
• Logistical requirements
– Near real time availability of data
– Site is accessible to researchers
– Existing site facilities
– Heritage of scientific studies to build from
– Long term commitment by the sponsor/host
– Agreement with SMAP project
• Setting up a process now.

13. SMAP Cal/Val SM Core Validation Sites
• SMAP project priorities
– An area that is homogeneous or has a uniform
mixture of land covers at the product scale
– Represents an extensive or important biome
– Complement the overall set of sites
– Operational by 2012

14. SMAP Cal/Val SM Core Validation Sites
• Next Steps
– Survey candidate sites.
– Evaluate the effectiveness of the ongoing SMOS
validation program.
– Decide on appropriate mechanism for
collaboration.
– Workshop

15. SMAP Cal/Val: Pre-launch
Approach
• ATBD identified activities • Satellite Products
that will improve – AMSR-E, SMOS, Aquarius
algorithms and products • Field Campaigns
– Past
• SGP, SMEX….
• SMAPVEX08
– Ongoing
Just completed • Canadian campaign (CanEx)
• Australia campaign (SMAPEx)
• San Joaquin Valley experiment
– Future
• SMAPVEX ??
• Establish infrastructure • In situ sensor testbed
necessary for post-launch • Tower and aircraft SMAP simulators
Cal/Val • Core validation sites
• Collaboration

16. CanEx SM 2010: CSA and NASA
• Primary mission objectives: (1) validation of SMOS
brightness temperature and soil moisture products and
(2) concurrent time series of active and passive
microwave observations for SMAP passive, active,
and combined soil moisture algorithms.
• Flight dates:
– June 2-15 Kenaston (KEN) (7 dates) (agricultural)
– June 16 BERMS (1 date) (forest)
• Other mission considerations
– Both domains include two independent SMOS grid
footprints.
– Coordination with SMOS over passes.
– Calibration and scaling of permanent in situ networks

17. CanEx Permanent In Situ Networks
Environment
Canada
BERMS
• Close to desired
SMAP Core
University of
Guelph
Validation site
requirements
Environment
Canada
Kenaston

18. CanEx SMOS Pixel Centers and Aircraft Coverage
SMOS products are
at ~40 km
resolution and
gridded at ~16 km.
Aircraft logistics
limit the size of
the coverage
domain.
Each area
includes ~ 2
independent
pixels (~33 by 70
km).

19. CanEx Campaign Soil Moisture Sites
Ground sampling
sites included most
permanent sites, the
BERMS temporary
network, and 50
additional sites
selected to be
representative of
BERMS Temporary
domain, provide
Network
spatial coverage,
• Will provide a
and support
longer record for
multiple scaling
SMOS/BERMS and
objectives.
to establish scaling of
the limited permanent
59 network.

20. CanEx Campaign Aircraft
NASA G-III UAVSAR: L-band fully polarimetric
radar (Swath 20 km, resolution 6 m).
Multiple lines were required to
provide coverage between 35 and 45o.
Environment Canada Twin Otter
L-band dual polarization radiometer,
40o (single beam, resolution 3 km).
Multiple lines were required to
provide coverage .
6.9, 19, 37 and 89 GHz radiometers,
53o (single beam, res. are 1.3 km for
6.9 GHz and 0.8 km for the others)

21. CanEx Summary
Date Saskatoon Prince Albert Aircraft Flights Satellite Coverage Note
Daily Rainfall Daily Rainfall Site
(mm) (mm)
May 22-30 67.3 68.4
June 1
Significant Rain
2 0.7 KEN SMOS
3 9.8 14.8 SMOS
4 2.2
5 6.8 KEN SMOS
6 0.2 KEN
7 5.5 2.8
Re-wetting
8 16.9 7.2 SMOS Partial Twin Otter
9 KEN
10 5.5 4.0 SMOS
11 13.2
12
13 0.4 KEN SMOS
14 0.1 KEN
15 0.3 KEN SMOS Only UAVSAR
16 0.2 BERMS SMOS

22. CanEx Campaign Ground Conditions
Wettest Spring…ever
Waterlogged soils resulted in limited
planting and tillage

23. CanEx Kenaston Area
Composite radar image
(HH-red, VV-blue, HV-
green)
65o
25o June 5, 2010

24. SMAP Major Field Campaigns
ver. 07/10
• SMAPVEX08
Year/ 1 2 3 4
Quarter
– High priority design/algorithm issues
• SMAPEx (Australia)
2008
SMAPVEX08 – 4 one-week campaigns to span four
seasons
2009 SMOS
– Aircraft Radar/Radiometer
2010 • CanEx-SM (Canada)
SMAPEx SMAPEx – Two-week soil moisture campaign
CanEx-SM
– Aircraft Radar/Radiometer
2011 Aquarius GCOM-W
SMAPEx CanEx-FT • CanEx-FT (Canada)
2012 SAOCOM – Two-week freeze/thaw campaign
SMAPVEX12 – Aircraft Radar/Radiometer
2013 • SMAPVEX12
– Major hydrology campaign
2014 SMAP – Long duration
– Aircraft Radar/Radiometer
2015 SMAPVEX15 SMAPVEX15 SMAPVEX15
• SMAPVEX15
– Extended campaign for both SM and
FT
– Long duration
Satellite Launch in Red – Aircraft Radar/Radiometer

25. SMAP Cal/Val Key Points
• Pre-launch Cal/Val is driven by the Algorithm teams
and the post-launch mission requirements.
• Timeline has a major impact!
• Core Validation Sites must be established.
• Field campaigns
– Recent field campaigns have exploited partnerships.
– CanEx, SJV, and SMAPEx have all been successful.
– Planning for a 2011 freeze-thaw activity is beginning.
– Broad input is needed for the next campaign.
• Cal/Val Workshop Week of May 3-5, 2011 (S. Calif.).