Microwave Remote Sensing for probing

planetary surface

NISAR WORKSHOP

17th-18th November, 2014, SAC-Abad

Suresh Raju CSpace Physics Laboratory,

VSSC-ISRO,Trivandrum-22

c_sureshraju@vssc.gov.in

Suresh Raju, et al., IEEE GSRL. V.10.,No.5, 2013

Γ−+ )1( eTd o w n

(3) Emission from the surface

Satellite Radiometric Measurements & Emissivity Estimation –Earth & Planet

upb T=T21 3

=Γ transmisitivity of the atmosphere

)ΓT(TΓTTT

=edownskin

downupb

−

−−

Γ+ eTs

(1) Emission from the atmosphere(2) atmospheric emission reflected

from the surface

Land surface microwave emissivity at 19,37 & 90 GHz

Tinu, Suresh Raju, et al., IEEE Trans. Geosci. Remote Sen. (2014)

Global land cover

Polarization Difference (eV – eH) at 19 GHz and surface condition

TRMM‐TMI Emissivity map at 19 GHz (H) spatially merged with Ganga & Brahmaputra river systems for the post flooded period (sept.2010)

BRAHMAPUTRA

Nepal BhutanChina

26°0'0"N

GANGAIndia

Bangladesh

Myanmar (Burma)

24°0'0"N

22°0'0"N )( HV eeMyanmar (Burma)

94°0'0"E92°0'0"E90°0'0"E88°0'0"E86°0'0"E84°0'0"E82°0'0"E80°0'0"E78°0'0"E76°0'0"E

20°0'0"N

100)()(

HV

HV

eeeeNPI

NepalChina

BhutanN

India Bangladesh

N

N

Myanma

N

N

96°094°0'0"E92°0'0"E90°0'0"E88°0'0"E86°0'0"E84°0'0"E82°0'0"E80°0'0"E78°0'0"E

Microwave Remote Sensing Techniques

Radar Equation- •Planck’s Blackbody radiation law

σπ

λ43)4(

22

R

GtPrP =→

PhysicalB TeT ⋅=

−=

1

122

3

KThff

echfB (Wm-2sr-1Hz-1)

σ - Radar backscattering coefficient (dB)

function of Target parameters & system parametersσ

(K)

e - function of Target & system parameters

•Target parameters: Roughness -h, Dielectric property ( ), &temperature (T), geometric shape

•System parameters: wavelength( ), Incidence angle( ), Polarization (p)

⋅= λθεσ ,,,, phR ),,,,(1

⋅−= λθε phRe

λ θ

ε

R

Pt

Pr

A combined measurements of the radar and radiometer, enables to separate out the effects of surface roughness.

ACTIVE SENSING-Radar Passive SENSING-Radiometry

Projection of Science Plan & NISAR Data Utility1. Combined use of NISAR and microwave radiometric data

land surface characterization Soil moisture and wet land study correlating with Precipitation

and convection studies Flooded area mapping Microwave characterization Vegetation cover Surface and subsurface studies over desert/arid region

2. Airborne NISAR Ground-truth and Cal-Val activity over Indian Tropical/Equatorial region

Requirement:•NISAR and Microwave Radiometric data

•Airborne Pre and post launch campaign of NISAR

•Extension of NISAR to Radiometric observation mode also?

(MAGELAN-for Venus mission)

Geology of Arabian peninsula

Soil Type map – FAO 1994

Emissivity 19 GHz (H ) – using TRMM (Dec 2011)