BEGEO

DE ULTIEME CONNECTIE / LA CONNEXION À

L'ÉTAT PUR

SAR interferometry: Time series and multi-

sensor approach for vertical and horizontal

displacements monitoring

Dominique Derauw1,2, François Kervyn3, Nicolas d’Oreye2

1 Centre Spatial de Liège

2 Royal Museum of Central Africa

3 European Centre for Geodynamics and Seismology (Luxembourg)

Earth Observation & Remote Sensing

Remote Sensing

Active sensor Passive sensor

SAR Remote Sensing

• Global coverage at repeated

cycle

• Insensitivity to external

illumination

• High sensitivity - large dynamic

• Very large area coverage

• Day and night (➫ X2)

• Insensitivity (or nearly...) to cloud

coverage ➫ All weather (➫ X5)

SAR interferometry

SAR interferometry

• The interferometric phase contains:

➫ The orbital phase

➫ The topographic phase

➫ The atmospheric phase delay

➫ The displacements phase

➫ Noise

SAR differential interferometry - DInSAR

© "Robert A. Eplett/CAL EMA"

California Governor's Office of

Emergency Services

Landers earthquake - 1992

Time series

• DInSAR gives a « one-shot » view of observable displacements

➫Post-seismic measurements

• To observe long-term displacements, one can use time-series and

combine DInSAR measurement sequences:

➫PSInSAR

➫MSBAS

MSBAS

• Multidimensional Small BAseline Subset approach:

➫Differential phase time series

➫Multi sensor / multiple acquisition geometries approach

• Allows retrieving East-West and

vertical displacement components

Funu landslide monitoring

• Test site: Funu, Bukavu, RDC

Funu landslide monitoring

CSK

S1

CSK + S1

(M)SBAS displacement rates

measurements: Limburg Mining area • Example of CSK line of sight

displacement rate monitoring:

(M)SBAS displacement rates

measurements: Limburg Mining area • Example of CSK line of sight displacement rate monitoring:

➫ zoom on Lummen highway cross:

Dynamic coherence monitoring

• Coherence is a quality indicator of InSAR phase measurement.

• It is also an indicator of scatterers characteristics and distribution

change between acqusition.

• It can thus be used as a dynamic indicator of scene changes:

➫Wildfires

➫Floods

Dynamic coherence monitoring: Wildfires

Dynamic coherence monitoring: Floods

Dynamic coherence monitoring: Floods

Conclusions

• Nowadays profusion of SAR data, including Copernicus ones,

allows performing continuous displacement monitoring of terrains

and manmade structures.

• CSL and ECGS developed an integrated tool, merging respective

expertises that is now used to perform continuous monitoring of

RMCA test sites in North Kivu, RDC.

Thank you For your attention

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