La tecnica PSInSAR per la mappatura dei fenomeni …EC... · dei fenomeni franosi a scala...

La tecnica PSInSAR per la mappatura dei fenomeni franosi a scala

regionale: casi di studio in regioni alpine ed appenniniche

La tecnica PSInSAR per la mappatura dei fenomeni franosi a scala

regionale: casi di studio in regioni alpine ed appenninichealpine ed appenninichealpine ed appenniniche

Geology and Information Technology3 – 5 giugno 2008Offida (AP)

M. Bianchi, G. Falorni & A. Tamburini(1) Tele-Rilevamento Europa - T.R.E. S.r.l.,

MILANO (Italy)

Copyright - Tele-Rilevamento Europa - 2004

COPYRIGHT - Tele-Rilevamento Europa 2008 1

OutlineOutline

• Overview of the Permanent Scatterers (PSInSARTM) technique

• Combining ascending and descending PS: why?g g g y• Examples of PS contributions to landslide

mapping and monitoring:pp g g− The IFFI Project in Valle d’Aosta

− Updating a landslide inventory in the Arno River basinUpdating a landslide inventory in the Arno River basin

• Pros and Cons of PSInSARTM


PS: “good” radar targets for measuringground displacementsPS: “good” radar targets for measuringground displacementsground displacementsground displacements

R1

R22nd acquisition

Permanent Scattereraffected by movement

1st acquisition

∆RRange variation

[mm]


What is a Permanent Scatterer?What is a Permanent Scatterer?

Targets with radar returns that are stable over time:buildings, roads, pipelines, antennas, poles, rock outcrops, ...g p p p p


PSInSAR™: multi image approachPSInSAR™: multi image approach

R1

R2

Rn

∆R12

disp

lace

men

t∆R…n

PS

∆R12

∆R…n


St1 t2 tn…

time

Ascending and Descending PS exampleAscending and Descending PS example

Ascending DescendingVD>0

Vert

VD>0

East


LOS DesceLOS Asce

VA<0

Estimation of vertical and E-W horizontal displacements from Ascending and Descending dataEstimation of vertical and E-W horizontal displacements from Ascending and Descending data

Ascending geometry Descending geometry

d0 d0+d1 d0+dn

d0 d0+d1 d0+dn

H

V 0Est

Vr

Vd>0VrEPS

VrH r

Va<0


T0 T1 Tn

Case studiesCase studies

Valle d’AostaValle d’AostaValle d AostaValle d Aosta


The IFFI Project in Valle d’AostaThe IFFI Project in Valle d’Aosta

The Italian Landslide Inventory (IFFI Project):y ( j )

• identify and map landslidesover the whole Italian

i b dterritory, based onstandardized criteria

• started in 1997• started in 1997

• results published in 2007


The IFFI Project in Valle d’AostaThe IFFI Project in Valle d’Aosta


PS processing Valle d’AostaPS processing Valle d’Aosta

• Satellite : ERS1 - ERS2

• AOI: 3.264 km2

• Regional PS Analysis (RPSA)Regional PS Analysis (RPSA)

• Acquisition geometry: ascending anddescending

• PS identified:138 095 Ascending234 913 D di234 913 Descending


From IFFI website:http://www.mais.sinanet.apat.it/

Processing ERS1-ERS2 Valle d’AostaProcessing ERS1-ERS2 Valle d’Aosta

Ascending data:Ascending data:Track 301: images 32 (1995-2000) Track 29: images 50 (1993-2000)Track 29: images 50 (1993 2000)

Descending data: Track 294: images 80 (1992-2000) Track 22: images 89 (1992-2001)


What can PS contribute in regionall l ?

What can PS contribute in regionall l ?scale analyses?scale analyses?

• Cross check of landslide areal extent

• Detect unmapped landslides

• Assess landslide activity• Assess landslide activity


What can PS contribute?What can PS contribute?

Landslide AActivity: confirmedB d difi d

A

Boundary: modifiedLandslide BActivity: modifiedBoundary: modified

BF

activeinactive

activeinactive DC

F

C’Landslide F

activeinactive

inactivedormant E

Landslide FActivity: modifiedBoundary: confirmed Landslide D

New detection!

L d lid C


dormant Landslide ENew detection!

Landslide CActivity: modifiedBoundary: modified

Apennines: the Arno River basinApennines: the Arno River basin

• 3 operationalpservices:– Landslide mapping– Landslide monitoring– Susceptibility assessment

• Test sitesTest sites– Arno catchment– Liri Garigliano Catchment– 3 Swiss cantons

COPYRIGHT - Tele-Rilevamento Europa 2008

European Space Agency

Arno River BasinArno River Basin

PratoPistoia

Firenze

Prato

Pisa

Arezzo

Attribute ValueBasin area 9130 km2

Number of mapped landslides 27 270SAR images processed (1992-2002) 350Total number of PS 591 263


PS in mountainous areas 265 177

Descending PS 1992-2002Descending PS 1992-2002

Total:327 942 PS


Ascending PS 1992-2002Ascending PS 1992-2002

Total:263 321 PS


Landslide inventory mapLandslide inventory map

74% earth slides and flows19% shallow landslides and creep

27 270 mapped landslides

19% shallow landslides and creep5% debris flows2% others


27 270 mapped landslides8.8 % landslide density

LegendLandslide polygons

attiv

instab

Landslidelines

attivinatt

PS and landslide mapinstab

quiescinatt

PS ascendingVel (mm /y)") -29.18 - -5.00") -4.99 - -3.00

PS DescendingVel (mm /y)$+ -29.18 - -5.00

$+ -4.99 - -3.00") -2.99 - -1.25

") -1.24 - 1.25

") 1.26 - 3.00

") 3.01 - 5.00

") 5.01 - 29.05

$+ -2.99 - -1.25

$+ -1.24 - 1.25

$+ 1.26 - 3.00

$+ 3.01 - 5.00

$+ 5.01 - 29.05

G PS_rufina


Monitoring of single landslidesMonitoring of single landslides

!( -4 99 - -3 00

!( -29.18 - -5.00Vel (mm/y)APSACarbonile

landslide

!( 3.01 - 5.00

!( 1.26 - 3.00

!( -1.24 - 1.25

!( -2.99 - -1.25

!( 4.99 3.00

!( 5.01 - 29.05

!( 3.01 5.00


Carbonile landslideCarbonile landslideStabilization works(drainage wells & subhorizontal drainages)

quiesc

instab

attiv

Landslide

Arno River ActiveInactiveDormant

Vel (mm/y)APSA

stabilizzataB

B

o a tStabilized

!( -1.24 - 1.25

!( -2.99 - -1.25

!( -4.99 - -3.00

!( -29.18 - -5.00

A A

5

!( 5.01 - 29.05

!( 3.01 - 5.00

!( 1.26 - 3.005


Revised hazard area with PS dataRevised hazard area with PS data


Pros of PSInSAR™Pros of PSInSAR™

Wide area investigations (e.g. catchments, DSGD)DSGD).

Vertical and E-W horizontal displacements can be retrieved in areas covered by both ascendingbe retrieved in areas covered by both ascending and descending data.

Historical database available from ERS-1 andHistorical database available from ERS 1 and ERS-2 (1992-2001) and RADARSAT-1 (2003-2008 for Italy) archives.

Useful for updating landslide inventories (landslide boundaries and activity; detection of unmapped landslides)


unmapped landslides)

Cons of PSInSAR™Cons of PSInSAR™

Areas without PS

The number and distribution of PS can’t be foreseen beforehand

Minimum 25 30 radar datasets are required forMinimum 25-30 radar datasets are required for processing

Revisiting time ~ 30 days (35 days for ERS 24Revisiting time 30 days (35 days for ERS , 24 days for Radarsat)

Can only measure slow movements (< 20 cm/yr)y ( y )

Can’t measure displacements in N-S direction


DevelopmentsDevelopments

• New missions will deploy constellations of satellites (e.g. CosmoSkyMed) which will have:• Lower revisting time (~ 14 days)Lower revisting time ( 14 days)• Specific configuration for SAR interferometry

• Ongoing development of processing algorithmsOngoing development of processing algorithms

• Opening of new branch of TRE in Canada


Grazie!Grazie!Grazie!Grazie!Marco BianchiMarco Bianchi [email protected]

Giacomo [email protected]

Andrea [email protected]


La tecnica PSInSAR per la mappatura dei fenomeni …EC... · dei fenomeni franosi a scala...

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