IGARSS 2011_AHMED GABER.ppt

ASSESSING THE POTENTIAL OF GROUNDWATER RESOURCES WEST ASSESSING THE POTENTIAL OF GROUNDWATER RESOURCES WEST

OF ASWAN, EGYPT, USING ALOS/PALSAR POLARIMETRIC OF ASWAN, EGYPT, USING ALOS/PALSAR POLARIMETRIC

INFORMATIONINFORMATION

Ahmed Gaber (Ahmed Gaber ( جابر جابر أحمد * Magaly Koch **, Motoyuki Sato **, Magaly Koch **, Motoyuki Sato ,*((أحمد* Center for Northeast Asian Studies, Tohoku University, Sendai, Japan

**Center for Remote Sensing, Boston University, Boston, MA, USA

IGARSS 2011, 24-29 July, Vancouver, Canada

[email protected]

mailto:[email protected]

Talk Outline

Research Background

Radar Polarization Transformation of ALOS/PALSAR

Radar Polarization Filtering

Preliminary results

Field Validation

Conclusion

2IGARSS 2011, 24-29 July, Vancouver, Canada

© Freeman et. al., 2007

Radar Penetration Capability in the Desert Areas

Research Background


IGARSS 2011, 24-29 July, Vancouver, Canada

Research Background

© Freeman et. al., 2007

4

The penetration capability is based up on both the observational conditions (sensor)

and the medium characteristics (environmental conditions) , such;

The penetration depth is spatially dependent

Environmental conditionsSurface roughness

Moisture content

Dielectric constant

grain size

sand contaminants

Bulk density

Research Background


Observational conditions Wavelength

Polarization

Incident angle

Objective

Evaluate the use of ALOS/PALSAR full polarimetric data to

delineate and image the near surface structures in the desert

environment west the Nile River in Egypt.


Description of the Test Site


ALOS/AVNIR-2

Barqa Hill

Nile

Riv

er

Nile

Riv

er

Radar Polarization Transformation of ALOS/PALSARRadar Polarization Transformation of ALOS/PALSAR


© E. Pottier – J.S. Lee (2011)


Orientation angle: ψ˚ψ˚

Elipticity angle: χ˚χ˚

ALOS/PALSAR(HH, HV, VH, VV)


|SLL-SRR| |SLR+SRL| |SLL+SRR||SLL-SRR| |SLR+SRL| |SLL+SRR|

|SHH-SVV| |SHV+SVH| |SHH+SVV||SHH-SVV| |SHV+SVH| |SHH+SVV| |S11-S22| |S12+S21| |S11+S22||S11-S22| |S12+S21| |S11+S22|

|S11-S22| |S12+S21| |S11+S22||S11-S22| |S12+S21| |S11+S22|

Linear Basis (Linear Basis (ψψ=45° & =45° & χ χ =0°) =0°)

Elliptical Basis (Elliptical Basis (ψψ=45° & =45° & χ χ =23°) =23°) Circular Basis (Circular Basis (ψψ=0° & =0° & χ χ =45°) =45°)Elliptical Basis (Elliptical Basis (ψψ=135° & =135° & χ χ =34°) =34°)

|S11-S22| |S12+S21| |S11+S22||S11-S22| |S12+S21| |S11+S22|

Elliptical Basis (Elliptical Basis (ψψ=45° & =45° & χ χ =11°) =11°)

|S11-S22| |S12+S21| |S11+S22||S11-S22| |S12+S21| |S11+S22|


Orientation angle: ψ˚ψ˚

Elipticity angle: χ˚χ˚

ALOS/PALSAR(HH, HV, VH, VV)

AVNIR-2


Radar Polarization FilteringRadar Polarization Filtering

Optimal Polarization Contrast Enhancement (O.P.C.E) method (Kostinski, and Boerner, 1987)


Buried fracturesSurrounding the fractures


The Proper Polarization State of Buried Fracture Imaging

iteration = 8

Final Contrast = 2.153422e+000

Optimal Transmit Polarizationg0 = 1.000000e+000g1 = 9.928611e-001g2 = 1.098681e-002g3 = 1.187688e-001

Optimal Receive Polarizationh0 = 1.000000e+000h1 = -9.832537e-001h2 = -1.133955e-001h3 = 1.426660e-001

Initial Contrast = 1.047321e+000

Buried fractures (Svv) and surrounding (Shh)



Polarization filtering effect: (a) before, and (b) after applying the O.P.C.E


Preliminary resultsPreliminary results

(a) ALOS/AVNIR-2, and (b) ALOS/PALSAR processed image

10 km 10 km10 km

(a) (b)


Ephemeral river

Ephemeral river

Ephemeral river

Bar

qa

Hil

l

Bar

qa

Hil

lB

arq

a H

ill

Field ValidationField Validation

Very dry soil moisture with values 0%, 0.3%, 0.6% and the maximum value is 1.7%

1) Measuring the soil volumetric moisture using (TDR)



εr = 3.04

The low moisture content and low RMS height are providing good The low moisture content and low RMS height are providing good

conditions for RADAR to penetrate relatively deepconditions for RADAR to penetrate relatively deep

The average hRMS = 0.01 cm


Soil moisture with values 0%, 0.3%, 0.6% and the maximum value is 1.7%


Acquiring GPR survey using 270 MHz shielded antenna

21 GPR profiles were surveyed



A A’

B B’

C C’

ALOS/PALSAR

Application point of viewApplication point of view

Extracted faults from (a) official geologic map, (b) processed ALOS/PALSAR data and (c) density map of highly fractured areas (brown color)


Application point of viewApplication point of view

SRTM-DEM, drainage patterns and watersheds surrounding Kom Umbo basin


ConclusionConclusion Circular polarization information of PALSAR L-

band data has been used in this study to detect hidden fault structures striking in various directions.

The Optimal Polarization Contrast Enhancement (O.P.C.E) method which maximizes the ratio of backscattered strength between faults (targets) and the surrounding sedimentary material (clutter) clearly defined the fault zones.

Faults that are largely undetectable on optical images or on the ground were detected on satellite radar images and confirmed with GPR.

These highly fractured zones are possibly favorable zones for groundwater accumulation. 22IGARSS 2011, 24-29 July, Vancouver, Canada

IGARSS 2011 24-29 July, Vancouver, Canada 25

Field Photographs;Field Photographs;

IGARSS 2011 24-29 July, Vancouver, Canada


2) Measuring the surface roughness using the Pinemeter

The average hRMS was 0.01 cm across all sites, with a maximum of 0.2 cm (almost flat)

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Hill shaded relief image has been generated from the SRTM Hill shaded relief image has been generated from the SRTM

Kom Umbo Kom Umbo

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Geologic map of Aswan (2005)Geologic map of Aswan (2005)

IGARSS 2011_AHMED GABER.ppt

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