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SPACE BORNE RADAR SPACE BORNE RADAR INTERFEROMETRIC MAPPING OF INTERFEROMETRIC MAPPING OF

PRECURSORY DEFORMATIONS OF PRECURSORY DEFORMATIONS OF A DYKE COLLAPSE, DEAD SEA, A DYKE COLLAPSE, DEAD SEA,

JORDAN JORDAN

Closson, Abou Karaki, al-Fughadclosson@mail.com

naj@paris.com

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The case study :

the collapse of the salt evaporation pond 19 of the Arab poatsh Company

1650

m

Ikonos : 19-10-2000

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The SEP costed 32 M Jordan DinarIt collapsed on March 22, 200055 M m3 brine to the Dead Sea in less than one our

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After the mid sixtiesThe Dead SeaDecrease from -392mTo -418m

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ERS Radar Images

Lisan Coastline

1961-1962

1993

1999

May, 29 1999

June, 30 1993

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SAR-based remote SAR-based remote sensing techniquesensing technique

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Remote sensing SARRemote sensing SAR

SAR = Synthetic Aperture RADAR (RAdio Detection And Ranging)

• SAR is a sensor able to generate high resolution images

• imaging sensor:

Allows the observation of the Earth surface in 2D

• exemple of another sensor :

Radar altimetre: provide data in one dimension. Allow generation of topographic maps

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• main characteristics of SAR images:

1. It is an active system (illuminate the area of interest with microwaves)

independant of solar illumination

allows measurement in day and night conditions

2. use micro-waves to penetrate through cloud cover

allows observations in cloud cover areas

remark: it alters the accuracy of measurements

3. Its a coherent system by opposition to visible remote sensing wich

use the incoherent light of the sun

allows the use of interferometry technic

SAR remote sensing - propertiesSAR remote sensing - properties

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4. SAR allows the observation of Earth surface properties that are not accessible to visible sensors

- rugosity, dielectric properties (through coherence images)

- possibilities to penetrate

- the vegetation (L band)

- ultra dry soil

- snow cap

5. The Sar resolution is independant of the distance between the sensor

and the objective

6. – Allows the utilisation of different polarization in transmission as well as

in reception :

HH, HV, VV, VH

- Allows the utilization of different frequencies

SAR remote sensing - propertiesSAR remote sensing - properties

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SAR applications

1. Geometric applications, based on the interferometric phase:

- Generation of digital terrain model (DTM)

Technic: SAR interferometry (InSAR)

- Control the deformations fields over the Earth surface

Technic: differential SAR interferometry (DInSAR)

2. Thematic application

- Change detection from coherence variation through time (soil erosion, flood)

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Deformation fields : principle

S

P

P’

M

M

S

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DInSAR

The differential interferometric phase is a sum of several components

Topo topographic phase Mov movement Atm atmosphere Noise noise of instruments

NoiseAtmMovTopoInt

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Subidence from 1995-1997

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