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MoistureMap: Multi-Angle Retrieval
Sandy PeischlPhD-candidate
Jeffrey Walker, Dongryeol Ryu, Christoph Rüdiger, Damian Barrett, Robert Gurney, Jetse Kalma, Yann Kerr, Ed Kim and John LeMarshall
MoistureMap: Multi-angle retrieval
Soil Moisture Ocean Salinity
SMOS records brightness temperature values over incidence angles from 0° to 55°
Improve accuracy of soil moisture retrieval using inversion scheme of L-meb by investigation of look angle effects on ancillary data
Source: www.smos-bec.icm.csic.es
Tilt 32°
Nadir
Earth
MoistureMap: Multi-angle retrieval
Bare soil:2
2
2
sincos
sincos1
r
rhe
2
2
2
sincos
sincos1
rr
rrve
Fresnel equation, where = sensor look angle r = dielectric constant relative to free space h,v = polarization
< '
'
soilpb TeTp
MoistureMap: Multi-angle retrieval
Bare soil:2
2
2
sincos
sincos1
r
rhe
2
2
2
sincos
sincos1
rr
rrve
Fresnel equation, where = sensor look angle r = dielectric constant relative to free space h,v = polarization
soilpb TeTp
MoistureMap: Multi-angle retrieval
Bare soil:
Source: Ulaby et al., 1986
soilpb TeTp
2
2
2
sincos
sincos1
r
rhe
2
2
2
sincos
sincos1
rr
rrve
Fresnel equation, where = sensor look angle r = dielectric constant relative to free space h,v = polarization
MoistureMap: Multi-angle retrieval
Vegetated soil:
vegvegvegsoilvegvegvegsoilsoilb TTTT )1()1()1()1()1(
coseveg
where,
is the transmissivity of the vegetation layer
Tveg is the physical temperature of vegetation (K)
Tsoil is the physical temperature of soil (K)
ω is the single scattering albedo of the vegetation
is the optical depth at nadir
and
veg
published in Davenport et al., 2005
Tbsoil
TbvegTbveg
+Tbsoil
MoistureMap: Multi-angle retrieval
Vegetated soil:
vegvegvegsoilvegvegvegsoilsoilb TTTT )1()1()1()1()1(
L < L’
<
'
'
coseveg
where,
is the transmissivity of the vegetation layer
Tveg is the physical temperature of vegetation (K)
Tsoil is the physical temperature of soil (K)
ω is the single scattering albedo of the vegetation
is the optical depth at nadir
and
veg
published in Davenport et al., 2005
MoistureMap: Multi-angle retrieval
Vegetated soil:
vegvegvegsoilvegvegvegsoilsoilb TTTT )1()1()1()1()1(
coseveg
where,
is the transmissivity of the vegetation layer
Tveg is the physical temperature of vegetation (K)
Tsoil is the physical temperature of soil (K)
ω is the single scattering albedo of the vegetation
is the optical depth at nadir
and
veg
published in Davenport et al., 2005
Tsoil = 298.15 KTveg = 298.15 KType = GrasslandVWC = 2; b = 0.15
MoistureMap: Multi-angle retrieval
Look Angle
Brightness Temperature
Transmissivity
Vegetation Temperature
Single Scattering Albedo
Soil Temperature
Emissivity
Vegetation
Soil
Vegetation Water Content
Soil Water Content
Soil Properties
Roughness
MoistureMap: Multi-angle retrieval
Polarimetric L-Band Multibeam Radiometer
• 2005 Tb-observations at six along-track view angles with 250 m resolution
• 2006 Tb-observations at six along-track view angles with 500 m resolution 0 1
K m
M erriwa P ark
L egend
S A S M A S S ite
N A F E foc us farm
H igh res o lution area
G round s am pling (250m )
G round s am pling (125m )
G round s am pling (62.5m )
m ultiangle flights
M ultiangle_ c overage
MoistureMap: Multi-angle retrieval
Outlook
understanding + modeling of incidence angle dependence on ancillary data
improved retrieval of soil moisture and related key variables
application to SMOS data+ verification using Murrumbidgee flights