MoistureMap: Multi-sensor Retrieval
of Soil Moisture
Mahdi Allahmoradi
PhD Candidate
Supervisor: Jeffrey Walker
Contributors:
Dongryeol Ryu, Chris Rudiger
Research Aim
This research will test the hypothesis that
more accurate soil moisture information can
be derived from SMOS if vegetation and soil
temperature information are derived from
other coincident remote sensing observations
at higher resolution.
Ground/RS Data, Models, …
SMOS
MoistureMap
SMOS overview
• SMOS
 Approximate launch date: May 2009
 Lifetime: Minimum 3 years
 Frequency: L-band (21cm - 1.4 GHz)
 Orbit: Sun-synchronous
 Overpass time: 6 am - 6 pm
 Temporal resolution: 3 Days
 Spatial resolution: 40 - 50 km (35 km
at centre of Field of View)
SOURCE: ESA
Tbp  epTsoil
Theoretical Aspect
The theory behind microwave remote sensing of soil moisture is
based on the large contrast between the dielectric properties of
liquid water and dry soil.
- For smooth bare soil (Planck’s law):
Tbp  epTsoil
- Vegetated soil (Tau - omega model):
equation of Ulaby et al. (1986)
Tb  1  1  e   veg  1   veg  1    Tveg   e veg Tsoil 
Vegetation Effect
Vegetation Effect:
  b*VWC
Jackson, 93
  b'*LAI  b' '
Wigneron et al. 07
Estimation of VWC using Vegetation indices
NDVI 
RNIR  RRED
RNIR  RRED
Reduced sensitivity to VWC changes in dense vegetation
(Jackson, 2004)
NDWI 
NIR  SWIR
NIR  SWIR
SWIR 1640 nm suitable for croplands
SWIR 2130 nm suitable for native vegetation (Maggioni, et al. 2006)
* b, b’ and b” are empirical parameters
Brightness Temperature → Soil Moisture
Tb
Modis
Data
Modis
Aqua
or
WindSat
Land Cover
Soil Temperature
Vegetation Water Content
or LAI
Surface Roughness
NAFE
ground
data
Soil Texture
Soil
Moisture
MTSAT 1R
&
WindSat
Data
Maybe
WindSat
Data
Spaceborne Remote Sensors
• MODIS
 Terra launched December 1999
 Aqua launched May 2002
 Design Lifetime: 6 years
 No. of Bands: 36
 Orbit: Sun-synchronous
 Overpass time: 10:30 am (Terra) – 13:30
pm (Aqua)
 Temporal resolution: 2 days
 Spatial resolution of bands: 250 m (1-2)
500 m (3-7) and 1 km (8-36)
SOURCE: NASA
Spaceborne Remote Sensors
• WindSat
 Launched on 6th January 2003
 Lifetime: Minimum 3 years
 Frequencies: 6.8, 10.7, 18.7, 23.8, 37.0
GHz
 Orbit: Sun-synchronous
 Overpass time: 6 am / 6 pm
 Spatial resolution: 8*13 km (for 37.0 GHz)
SOURCE: US NAVAL RESEARCH LAB
Spaceborne Remote Sensors
• MTSAT-1R
 Launched February 2005
 Lifetime: 5 years for meteorological
function, 10 years for aviation
function
 Bands: visible, Infrared (1-4)
 orbit: Geostationary
 Temporal resolution: 30 minutes
 Spatial resolution: visible (1 km
nadir), IR1-4 (4km nadir)
SOURCE: JAPAN METHEOROLOGICAL AGENCY
Algorithm Development
NAFE Ground Data
Algorithm
Remotely Sensed Data
Modis Aqua/Terra
Soil Temperature
WindSat
Vegetation Water Content
MTSAT 1R
SMOS
Soil
Moisture
NAFE Airborne Data
Verification