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