PanGeo project and the future exploitation of the ESA ... · PDF fileThe future step in the...
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4. Data availability The data available (fig.3) for PanGeo were : -Two series (1993-1999 and 2001-2009) PSI point data for Salzburg processed by Altamira; - various geological maps (1:50.000 and 1: 200.000 scale); - GEORIOS cadaster; - various digital elevation models (ASTER DEM and laserscan derived DEM); - the Urban Atlas ( landcover map for cities > 100.000 inhabitants). Austrian landslide catalogue assessment through the use of radar interferometry application” Being the „ on a national scale will bring together geological maps at various scales, the GEORIOS landslide cadaster (5), the CORINE land use map, the ESRI snow cover map, the HISTALP (6) snow cover and precipitation historical data, “eHYD” data warehouse (7) for cumulated daily rain weather stations, the ASTER DEM digital elevation model. Those layers of information (fig. 4) will be compared with DINSAR and advanced DINSAR products obtained by processing a series of radar SAR images. Geological maps Georios cadaster Urban Altlas DEM PSI data ^ _ eHYD weather stations orbit 358 ERS coverage HYSTALP snow stations October snow probility (%) 10 - 20 20 - 30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90 90 - 92,5 92,5 - 95 95 - 100 ESRI snow days with snow 50 100 150 200 250 300 365 The PSI predictability model (fig.5) (8) was tested successfully on the PSI data delivered for PANGEO. The ascending orbit give the higher probability to find mass movements mapped as very slow on GEORIOS. Around 500 features with extent > 10 hectares are susceptible to be detected in motion by using classic two pass DINSAR method.Through EOLI-SA software the first couple of images for the orbit 86 was ordered via ftp and analysed with NEST software. Since the interferogram covers alpine areas the date chosen were in August and the time between two acquisitions was 2 years (97-99). The first interferogram is unwrapped but showed good coherence over montaineous areas (9). The phase unwrapping it´s going to be tested with SNAPHU and MATLAB alghoritms. The future step in the analysis is to use GMTSAR (10) to perform the A-DINSAR focused on 2 sample sites. 5. Software processing PSI probability (%) 0 - 10 10 - 20 20 - 30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90 90 - 100 Ascending orbits Descending orbits Fig.5: PSI predictability model describing the probability to find persistent scatters overall Austria. Fig.4: Wheater stations (eHYD) for orbit 358 and HISTALP snow probability compared to the ESRI snow layer. 6. Preliminary results and their validation After having visualised PSI data, geo-hazard data and ancillary data together the main attention was draw where maximum rate of subsidence (in mm/year) in both series of descending orbit data were found (red and orange points). Two main areas affected by a pattern of subsidence driven displacement and two characterised by punctual evidences were examined. The latter are positioned very close to landslides mapped in the 1:50.000 scale geological map and in GEORIOS. The former areas, at the first sight, showed any geological evidences supporting instability apart for the case of Seekirchen am Wallersee (fig. 9) where there is a well-documented history of subsidence causing failure of a series of buildings (11). The validation nd work on the field was undertaken the 22 of May 2012 in Salzburg urban area and surroundings. The survey revealed for the punctual areas good feedback since on Mülltal evidence on the field of three creep mass movement were mapped on „Eisrand Terrasse”formation (fig.7c). Whereas on the Heuberg hill the satellite was able to spot a minor movement of a retention wall; here it was possible to map a rotational landslide imposed on „Rhenodanubian Flysch”(fig.8). In Langwied, a central area of Salzburg, instead three buildings showed cracks (fig. 6c). Further exams by combining boreholes and levelling data will be attempted in order to clearly define the motion occurred in urban areas. Fig.6a, 6b, 6c: Location of the two buildings presenting cracks (Bachstraße 9 and 32); both GEORIOS and geological map categorised the site as alluvial fan. Fig.9: Underlined measurements indicated similar subsidence rate than (10-12 mm/y) those obtained from the ers PSI. (geoland web application) Fig.7a, 7b, 7c: Location of two out of three creep mass mapped on Mülltal on würmian „Eisrand Terrasse”. Fig.8:Mapped rotational landslide sliding northwestward, the lithologhy is Flysh; movement of retention wall indicated by the yellow point (-4 mm/y). 7.Conclusions The PSI data available for Salzburg were very useful for the detection of subsidence and gravitative phenomena. This technique allows for the discovery of new terrain motions and for the monitoring of known ones, furthermore it´s been used for the classification of mass movement based on their activity. The validation on the field showed a very good reliability of the data since on the main hot spots visited, with movement > -4 mm/y, it was possible to detect some indication of ground or building instability. Being the method robust and reliable it supposed to be more intensively adopted by municipalities which are concerned for infrastractures planning. ESA radar archive in Austria it´s an ongoing project which is supposed to achieve similar results. The use of the 1. http://www.eea.europa.eu/data-and-maps/data/urban-atlas 2. http://www.pangeoproject.eu/ 3. http://ceos.esa.int/plenary16/papers/plenary16_doc14_dmsg_final/final_report/DMSG_final.pdf 4. 5. Tilch N. et al. (2011) The data management system GEORIOS of the geological survey of Austria, Poster presentation 6. http:// J. A. Richards (2009): Remote Sensing with Imaging Radar – Springer, Berlin. www.zamg.ac.at/histalp/ RocExs 2011. 8. Literature 7. http://gis.lebensministerium.at/ehyd 8. D. Notti et al. (2010) Assessment of the performance of X-band satellite radar data for landslide mapping and monitoring: Upper Tena Valley case study - Nat. Hazards Earth Syst. Sci., 10, 1865–1875 9. H. Roth et al (2002) IDNDR-Fernerkundung -Institut für Metereologie und Geophysik der Universität Innsbruck. 10. D. Sandwell, et al.(2011). GMTSAR: An InSAR Processing System Based on Generic Mapping Tools -Scripps Institution of Oceanography. 11. www.lese-seekirchen.at/gv_ausschuesse/GV Protokolle/2005-GV-08-2005-03-29.pdf a b a b c c 1.What is PanGeo? PanGeo is a collaborative project of the EC‘s Seventh Framework Program aimed at mapping and cataloguing in a web GIS portal natural and anthropogenic geo-hazard in Europe. The involvement of European geological surveys , ESA qualified PSI (Persistent Scatterers Interferometry) providers, together with the makers of the GMES Land Core Service “Urban Atlas”(1), insures state of the art contribution on hazard and mapping detection in urban and semi-natural environments. Salzburg (fig. 1) and Vienna are only two out of 52 cities investigated in PANGEO. The Persistent scattering Interferometry technique enables to detect terrain motion and the correlation with geological information and ancillary data is very important since it enable analysts to investigate and map specific geo- hazards. PSI (1992-1999 and 2003-2009) is one of the gathered information needed for the realisation of the ground stability layer. By combining such a layer with a hypertext, it will be possible to visualise natural and anthropogenic instabilities on the GIS PanGeo portal (2). This portal is meant to be a main reference for local authorities who deal with risk management and assessment. Fig.1: project area PanGeo 2. The use of the ESA radar archive in Austria The “Austrian landslide catalogue assessment through the use of radar interferometry application” it´s the title of the project proposed by the GBA which has been approved by the ESA in April 2012. The aim of the project is to improve the GEORIOS landslide cadaster of certain regions of Austria using Differential InSAR technique processing ERS and Envisat images provided free of charge from the ESA. The cost effective strategy to exploit the ESA Radar SAR archive in Austria is based on the fact that in mountainous areas major triggering events could cause over-aggravation phenomena on instable slopes (3). The DINSAR technique could prove if catastrophies activates new or re-activates previous mass movements. 3 SAR ascending coverage for Austria Orbit 444 Orbit 172 Orbit 129 Orbit 358 Orbit 86 Orbit 315 Orbit 43 Orbit 272 2 Selection ERS and ENVISAT products Master Slave EOLI-SA data ordering short temporal baseline (35 - 385 days) short geomerical base-line small doppler centroid 100% overlapping of 2 scenes Aug. Sept. Oct. Nov. April Snow cover verification March Level 1 SLC Level 0 raw Rain verification acquisition day 1 day before 1 day after Threshold < 6mm/d Aug. Sept. Oct. Nov. April Snow cover verification March Rain verification acquisition day 1 day before 1 day after Threshold < 6mm/d 1 pre-triggering post-triggering 4 DINSAR processing Differential interferogram formation with a pair of SAR images. Accuracy: 3mm year landslide extension > 10 ha Windows Open source software A-DINSAR processing (or PSI) LINUX Open source software Use of large multi-temporal stacks of SAR images for stable targets motion detection. Accuracy: 0,1 -1 mm/year good pixel resolution (20 x 20 m) 5 Fig.2: Work flow for the SAR processing of the project. 3. Methods overview By reviewing historical rain, snow, flood and landslide events it‘s possible to apply a kind of pre-seismic and post-seismic approach the so called “pre-triggering and post-triggering” method (fig.2). HISTALP snow data combined with the ESRI snow cover layer allows for the discrimination of the probability to find snow free areas in specific months of the year. More than 1200 local weather rain stations allows for the right choice in terms of date of image acquisition; being the humidity a factor which introduces a high atmospheric noise on the radar signal (4). A predictability PSI layer for ascending and descending orbits by using CORINE data and DEM derived slope and aspect map was created and compared to the GEORIOS landslide cadaster of Austria. AGIT Symposium und Fachmesse Salzburg, 04.- 06. July 2012 Tel: +43-1-7125674-0 Fax: +43-1-7125674-56 393 [email protected] www.geologie.ac.at Geologische Bundesanstalt Österreich - Neulinggasse 38, A-1030 Wien PanGeo project and the future exploitation of the ESA Radar SAR archive in Austria Filippo Vecchiotti, Arben Kociu, Edmund Winkler Nils Tilch, Fig.3: Data availability in for Salzburg urban area. PanGeo
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Transcript of PanGeo project and the future exploitation of the ESA ... · PDF fileThe future step in the...
4. Data availabilityThe data available (fig.3) for PanGeo were :-Two series (1993-1999 and 2001-2009) PSI point data for Salzburg processed by Altamira; - various geological maps (1:50.000 and 1: 200.000 scale); - GEORIOS cadaster;- various digital elevation models (ASTER DEM and laserscan derived DEM); - the Urban Atlas ( landcover map for cities > 100.000 inhabitants).
Austrian landslide catalogue assessment through the use of radar interferometry application” Being the „ on a national scale will bring together geological maps at various scales, the GEORIOS landslide cadaster (5), the CORINE land use map, the ESRI snow cover map, the HISTALP (6) snow cover and precipitation historical data, “eHYD” data warehouse (7) for cumulated daily rain weather stations, the ASTER DEM digital elevation model. Those layers of information (fig. 4) will be compared with DINSAR and advanced DINSAR products obtained by processing a series of radar SAR images.
Geological maps
Georios cadaster
Urban Altlas
DEM
PSI data
_̂ eHYD weather stations
orbit 358 ERS coverage
HYSTALP snow stations
October
snow probility (%)
10 - 20
20 - 30
30 - 40
40 - 50
50 - 60
60 - 70
70 - 80
80 - 90
90 - 92,5
92,5 - 95
95 - 100
ESRI snow
days with snow
50
100
150
200
250
300
365
The PSI predictability model (fig.5) (8) was tested successfully on the PSI data delivered for PANGEO. The ascending orbit give the higher probability to find mass movements mapped as very slow on GEORIOS. Around 500 features with extent > 10 hectares are susceptible to be detected in motion by using classic two pass DINSAR method.Through EOLI-SA software the first couple of images for the orbit 86 was ordered via ftp and analysed with NEST software. Since the interferogram covers alpine areas the date chosen were in August and the time between two acquisitions was 2 years (97-99). The first interferogram is unwrapped but showed good coherence over montaineous areas (9). The phase unwrapping it´s going to be tested with SNAPHU and MATLAB alghoritms. The future step in the analysis is to use GMTSAR (10) to perform the A-DINSAR focused on 2 sample sites.
5. Software processingThe PSI predictability model (fig.5) (8) was tested successfully on the PSI data delivered for PANGEO. The ascending orbit give the higher probability to find mass movements mapped as very slow on GEORIOS. Around 500 features with extent > 10 hectares are susceptible to be detected in motion by using classic two pass DINSAR method.Through EOLI-SA software the first couple of images for the orbit 86 was ordered via ftp and analysed with NEST software. Since the interferogram covers alpine areas the date chosen were in August and the time between two acquisitions was 2 years (97-99). The first interferogram is unwrapped but showed good coherence over montaineous areas (9). The phase unwrapping it´s going to be tested with SNAPHU and MATLAB alghoritms. The future step in the analysis is to use GMTSAR (10) to perform the A-DINSAR focused on 2 sample sites.
The PSI predictability model (fig.5) (8) was tested successfully on the PSI data delivered for PANGEO. The ascending orbit give the higher probability to find mass movements mapped as very slow on GEORIOS. Around 500 features with extent > 10 hectares are susceptible to be detected in motion by using classic two pass DINSAR method.Through EOLI-SA software the first couple of images for the orbit 86 was ordered via ftp and analysed with NEST software. Since the interferogram covers alpine areas the date chosen were in August and the time between two acquisitions was 2 years (97-99). The first interferogram is unwrapped but showed good coherence over montaineous areas (9). The phase unwrapping it´s going to be tested with SNAPHU and MATLAB alghoritms. The future step in the analysis is to use GMTSAR (10) to perform the A-DINSAR focused on 2 sample sites.
PSI probability (%)
0 - 10
10 - 20
20 - 30
30 - 40
40 - 50
50 - 60
60 - 70
70 - 80
80 - 90
90 - 100
Ascending orbits Descending orbits
Fig.5: PSI predictability model describing the probability to find persistent scatters overall Austria.
Fig.4: Wheater stations (eHYD) for orbit 358 and HISTALP snow probability compared to the ESRI snow layer.
6. Preliminary results and their validationAfter having visualised PSI data, geo-hazard data and ancillary data together the main attention was draw where maximum rate of subsidence (in mm/year) in both series of descending orbit data were found (red and orange points).Two main areas affected by a pattern of subsidence driven displacement and two characterised by punctual evidences were examined. The latter are positioned very close to landslides mapped in the 1:50.000 scale geological map and in GEORIOS. The former areas, at the first sight, showed any geological evidences supporting instability apart for the case of Seekirchen am Wallersee (fig. 9) where there is a well-documented history of subsidence causing failure of a series of buildings (11). The validation
ndwork on the field was undertaken the 22 of May 2012 in Salzburg urban area and surroundings. The survey revealed for the punctual areas good feedback since on Mülltal evidence on the field of three creep mass movement were mapped on „Eisrand Terrasse”formation (fig.7c). Whereas on the Heuberg hill the satellite was able to spot a minor movement of a retention wall; here it was possible to map a rotational landslide imposed on „Rhenodanubian Flysch”(fig.8). In Langwied, a central area of Salzburg, instead three buildings showed cracks (fig. 6c). Further exams by combining boreholes and levelling data will be attempted in order to clearly define the motion occurred in urban areas.
Fig.6a, 6b, 6c: Location of the two buildings presenting cracks (Bachstraße 9 and 32); both GEORIOS and geological map categorised the site as alluvial fan.
Fig.9: Underlined measurements indicated similar subsidence rate than (10-12 mm/y) those obtained from the ers PSI.
(geoland web application)
Fig.7a, 7b, 7c: Location of two out of three creep mass mapped on Mülltal on würmian „Eisrand Terrasse”.
Fig.8:Mapped rotational landslide sliding northwestward, the lithologhy is Flysh; movement of retention wall indicated by the yellow point (-4 mm/y).
7.Conclusions
The PSI data available for Salzburg were very useful for the detection of subsidence and gravitative phenomena. This technique allows for the discovery of new terrain motions and for the monitoring of known ones, furthermore it´s been used for the classification of mass movement based on their activity. The validation on the field showed a very good reliability of the data since on the main hot spots visited, with movement > -4 mm/y, it was possible to detect some indication of ground or building instability. Being the method robust and reliable it supposed to be more intensively adopted by municipalities which are concerned for infrastractures planning.
ESA radar archive in Austria it´s an ongoing project which is supposed to achieve similar results.The
use of the
1. http://www.eea.europa.eu/data-and-maps/data/urban-atlas 2. http://www.pangeoproject.eu/3. http://ceos.esa.int/plenary16/papers/plenary16_doc14_dmsg_final/final_report/DMSG_final.pdf4. 5. Tilch N. et al. (2011) The data management system GEORIOS of the geological survey of Austria, Poster presentation 6. http://
J. A. Richards (2009): Remote Sensing with Imaging Radar – Springer, Berlin.
www.zamg.ac.at/histalp/ RocExs 2011.
8. Literature7. http://gis.lebensministerium.at/ehyd 8. D. Notti et al. (2010) Assessment of the performance of X-band satellite radar data for landslide mapping and monitoring: Upper Tena Valley case study - Nat. Hazards Earth Syst. Sci., 10, 1865–18759. H. Roth et al (2002) IDNDR-Fernerkundung -Institut für Metereologie und Geophysik der Universität Innsbruck.10. D. Sandwell, et al.(2011). GMTSAR: An InSAR Processing System Based on Generic Mapping Tools -Scripps Institution of Oceanography.11. www.lese-seekirchen.at/gv_ausschuesse/GV Protokolle/2005-GV-08-2005-03-29.pdf
ab
a
b
c
c
1.What is PanGeo?
PanGeo is a collaborative project of the EC‘s Seventh Framework Program aimed at mapping and cataloguing in a web GIS portal natural and anthropogenic geo-hazard in Europe. The involvement of European geological surveys , ESA qualified PSI (Persistent Scatterers Interferometry) providers, together with the makers of the GMES Land Core Service “Urban Atlas”(1), insures state of the art contribution on hazard and mapping detection in urban and semi-natural environments. Salzburg (fig. 1) and Vienna are only two out of 52 cities investigated in PANGEO. The Persistent scattering Interferometry technique enables to detect terrain motion and the correlation with geological information and ancillary data is very important since it enable analysts to investigate and map specific geo-hazards. PSI (1992-1999 and 2003-2009) is one of the gathered information needed for the realisation of the ground stability layer. By combining such a layer with a hypertext, it will be possible to visualise natural and anthropogenic instabilities on the GIS PanGeo portal (2). This portal is meant to be a main reference for local authorities who deal with risk management and assessment.
Fig.1: project areaPanGeo
2. The use of the ESA radar archive in Austria
The “Austrian landslide catalogue assessment through the use of radar interferometry application” it´s the title of the project proposed by the GBA which has been approved by the ESA in April 2012.The aim of the project is to improve the GEORIOS landslide cadaster of certain regions of Austria using Differential InSAR technique processing ERS and Envisat images provided free of charge from the ESA. The cost effective strategy to exploit the ESA Radar SAR archive in Austria is based on the fact that in mountainous areas major triggering events could cause over-aggravation phenomena on instable slopes (3). The DINSAR technique could prove if catastrophies activates new or re-activates previous mass movements.
3
SAR ascending coverage for Austria
Orb
it 444
Orb
it 172
Orb
it 129
Orb
it 358
Orb
it 86
Orb
it 315
Orb
it 43
Orb
it 272
2Selection ERS and ENVISAT products
Master Slave
EOLI-SA data ordering
short te
mpora
l baselin
e (3
5 - 3
85 d
ays)
short geomerical base-line
small doppler centroid
100% overlapping of 2 scenes
Aug.
Sept.
Oct.
Nov.
April
Snow
cove
r ve
rific
atio
n March
Level 1 SLCLeve
l 0 ra
w
Rain
verific
atio
n
acquisition day
1 day before
1 day after
Threshold < 6mm/d
Aug.
Sept.
Oct.
Nov.
April
Sn
ow
cove
r verifica
tion
March Ra
in ve
rificatio
n
acquisition day
1 day before
1 day after
Threshold < 6mm/d
1
pre-triggering post-triggering
4
DINSAR processing
Differential interferogram formation with a pair of SAR images.
Accuracy: 3mm year landslide extension > 10 ha
Windows Open source software
A-DINSAR processing (or PSI)
LINUX Open source software
Use of large multi-temporal stacks of SAR images for stable targets motion detection.
Accuracy: 0,1 -1 mm/year good pixel resolution (20 x 20 m)
5
Fig.2: Work flow for the SAR processing of the project.
3. Methods overview
By reviewing historical rain, snow, flood and landslide events it‘s possible to apply a kind of pre-seismic and post-seismic approach the so called “pre-triggering and post-triggering” method (fig.2).
HISTALP snow data combined with the ESRI snow cover layer allows for the discrimination of the probability to find snow free areas in specific months of the year.
More than 1200 local weather rain stations allows for the right choice in terms of date of image acquisition; being the humidity a factor which introduces a high atmospheric noise on the radar signal (4).
A predictability PSI layer for ascending and descending orbits by using CORINE data and DEM derived slope and aspect map was created and compared to the GEORIOS landslide cadaster of Austria.
AGIT Symposium und FachmesseSalzburg, 04.- 06. July 2012
Tel: +43-1-7125674-0 Fax: +43-1-7125674-56 [email protected] www.geologie.ac.at
Geologische Bundesanstalt Österreich - Neulinggasse 38, A-1030 Wien
PanGeo project and the future exploitation of the ESA Radar SAR archive in Austria
Filippo Vecchiotti, Arben Kociu, Edmund WinklerNils Tilch,
Fig.3: Data availability in for Salzburg urban area.PanGeo
