kinematics of the slumgullionlandslide ground basedinsarsurvey€¦ · landslide kinematics...
TRANSCRIPT
30/05/2012
1
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 1
Kinematics of the Slumgullion Landslide revealed by Ground based InSAR Survey
P. Farina, P.P. Ricci & G. Barsacchi, Ingegneria Dei Sistemi, Pisa, ItalyW.H. Schulz, J.A. Coe, B.L. Shurtleff & J. PanoskyUnited States Geological Survey*, Denver, Colorado, USA
Speaker: Ing. Giorgio Barsacchi
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 2
Landslide kinematics
Traditional approaches for characterizinglandslide kinematics:
• Often require centimeters‐meters oflandslide movement to be effective
• Are labor intensive• Costly• Time consuming• Dangerous on inaccessible landslide.
We tested the IBIS‐L, which is a ground‐based,interferometric, syntetic aperture radar todetermine whether it could rapidly acquirekinematic data for a complex and large landslidelike the Slumguillon.
30/05/2012
2
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 330/05/2012 3
• 3.9 km long,
• 300 m wide
• Average thickness of 13 m
• Mean inclination 8°
• Sporadical Vegatation
• Moves persistently
Slumguillon Landslide ‐ Colorado USA
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 4
IBIS‐L capabilities
• Continuously measure (24x7) landslide movements with sub‐millimetric accuracy at long distance (up to 4 Km)
• All weather acquisition
• High spacial resolution
•Map the long term evolution of slow moving slopes to get a better knowledge of the rock mass strength
30/05/2012
3
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 5
Techniques behind GBInSAR systems
1. Stepped‐Frequency Continuous Wave (SF‐CW) technique resolves thescenario in the range direction, detecting the position in range of differenttargets placed along the radar’s line of sight;
2. Synthetic Aperture Radar (SAR) allows to obtain 2D high‐resolution radarimages by adding to the range resolution (fro the SF‐CW), the cross‐rangeangular resolution
3. Interferometric technique, computes the displacement of each pixels bycomparing the phase information of the radr signal collected at differenttimes.
GBInSAR sensors are based on three well‐known radar techniques:
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 6
60°
Observed area 4km
≅4200mt
≅2100mt
2km
IBIS
s
enso
r
2m
Pixel ΔR
ΔCR
Cross rangedirection
Range direction
IBIS
se
nso
r
Measure StationMeasure Station
Observed area
Pixel
Area coverage dimensions
Spatial resolutionTypical spatial resolutions:
• range: 0.5 m
• cross‐range: 4.3 m at 1000 m
High spatial resolution enables theidentification within a single bench ofseveral pixels, allowing the detectionof small failures.
SAR 2‐dimension
30/05/2012
4
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 7
The interferometric analysis provides data on object displacement bycomparing phase information, collected in different time periods, ofreflected waves from the object, providing a measure of the displacementwith an accuracy of less than 0.01mm.
TX
RX
TX
RX
d
TX
RX
TX
RX
d
First acquisition
Second acquisition
1ϕ
2ϕ
( )124ϕϕ
πλ −−=d
Interferometric capability
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 8
The combination of SAR and SF‐CW techniques allows the system toresolve the scenario into two dimensional pixels
Optical Image Power Map su DTM
SAR 2‐dimension
30/05/2012
5
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 9
IBIS‐L: configurations
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 10
Monitoring instruments
IBIS‐L from Ingengeria dei sistemi
Ground Based InSAR
Extensometer
GPS
30/05/2012
6
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 11
The Survey overview
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 12
• Few hours for the setup of the IBIS• 5 days of acquisition• The acquisition was set from 400m to 4 km• Acquisition time of 9.40 minutes
The IBIS campaign
30/05/2012
7
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 13
IBIS‐L survey result overimposed on a DTM
Cumulative displacement map Velocity map
Cumulative displacement mapAmplitude map
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 14
0 h
Cumulative displacement map
30/05/2012
8
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 15
24 h
Cumulative displacement map
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 16
48 h
Cumulative displacement map
30/05/2012
9
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 17
72 h
Cumulative displacement map
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 18
96 h
Cumulative displacement map
30/05/2012
10
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 19
120 h
Cumulative displacement map
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 20
Time histories
30/05/2012
11
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 21
Time histories
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 22
Extensometer vs InSAR
30/05/2012
12
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 23
InSAR vs GPS
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 24
Conclusion
• Displacement acquired by IBIS‐L compared favorably with measurements made using GPS and in situ instrumentation
• Within one day of surveying, kinematic elements comprising the landslide were clearly evident and correlated well with results from previous field mapping and analyses of aerial photographs
• The IBIS‐L is an instrument that can rapidly give a reliable characterization of a landslide
• The IBIS‐L technology can be used by civil protection authorities, road and railways infrastructure owners and research centers ‐ universities
30/05/2012
13
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 25
Georadar
Questions ?
Thanks for your attention
Giorgio Barsacchi Kinematics of the Slumgullion Landslide Revealed by Ground based InSAR Surveys 26
Georadar
Kinematics of the Slumgullion Landslide revealed by Ground based InSAR Surveys
P. Farina, P.P. Ricci & G. Barsacchi, Ingegneria Dei Sistemi, Pisa, ItalyW.H. Schulz, J.A. Coe, B.L. Shurtleff & J. PanoskyUnited States Geological Survey*, Denver, Colorado, USA