Use of polarimetric SAR for identifying oil Spills Susanne Lehner

Use of polarimetric SAR for identifying oil Spills Susanne Lehner

Use of polarimetric SAR for identifying oil Spills
Susanne Lehner
Forschungsstelle Maritime Sicherheit Bremen
DLR EOC
www.DLR.de/fl • Folie 2
> Vortrag > Autor • Dokumentname > Datum
Forschungsstelle Maritime Sicherheit Bremen
since 01.07.2013 in Bremen
DLR BF IMF
Remote Sensing Institute
Bremen
Forschungsstelle Maritime Sicherheit
What is new when adding TerraSAR to Oil Services?
• Just another (~two) satellite TS‐X , TD‐X overpasses, with swath up to coverage 200 km ? Service demonstrated by DLR in several EU, ESA projects, not chosen in CSN3 – why?
Further possibilities using TerraSAR:
• High resolution (1 m) observations around Oil Platforms – possibility to determine drift, volume, type of oil – is platform releasing too much?
• High resolution detection of ships and determination of environmental parameters like wind field, sea state, sea ice and iceberg parameters
• Dual Co‐Polarization Mode available: HH – VV, use of CPD filter gives possibility of distinction between Oil and look‐Alikes – better possibility to identify oil spills and seepage
DLR.de • Chart 4
> Lecture > Author • Document > Date
North Sea
Medterranean
Ship Scoured Spill
before entering EU Waters
More than 1,000 offshore oil and gas
installations in European waters mainly
concentrated in North Sea. Regular occurrence
of platform sourced pollution have been
monitored using TerraSAR-X since 2009.
EMSA’s mandate was extended to cover
response to oil pollution caused by offshore
installations.
High Resolution around Platforms from TerraSAR-X
DLR.de • Folie 6
Algorithm for NRT Oil Spill Detection
NRT Oil Spill Detection Service Image
Mode:
WideScanSAR,
ScanSAR,
StripMAP, SpotLight
(Product Type:
Multi Look Ground Range, MGD)
Product Delevery: WideScanSAR, ScanSAR,
StripMAP, SpotLight (Product Type: Multi Look
Ground Range, MGD)
Installed at the ground station Neustrelitz
as a reference station
Environmental Parameters – Use of remote sensing data with drift Model
Wind model direction TS‐X 2011/06/09 at 06:07 UTC 2011/06/09 at 06:00 UTC
slick coverage
Wind speed: ~ 6m/s TS‐X 2011/06/08 at 17:10 UTC Wind model direction slick coverage
2011/06/08 at 18:00 UTC
Wind speed: ~ 5m/s 5.80
Latitude
TYRA‐TCP‐A
5.65
UNKNOWN
5.50
4.60
4.80
5.00
5.20
Longitude
Wind speed from German weather service, DeMarine
Wind Speed and Drift from TerraSAR
Li et al, IEEE TGARSS, 2012
Li et al., JGR, 2014
Shao et al., IJRS, PORSEC 2012
> BFG > Susanne Lehner • Oct 2014
Oil Spill and Wind Speed features over the North Sea
DLR.de • Folie 10
Look Alike Features, e.g., Oceanic eddies in Baltic Sea
TSX-1.SAR.L1b-Stripmap 9/9/2011 Single / HH Descending path
Eddies detection
and
classification
Correlation and comparison with SST,
wind and current data
Oceanic eddies characteristics
and generation mechanisms
Tavri, Lehner
Scattering Polarimetry TerraSAR: Dual HH and VV available in NRT
AX
RX
T
AY
RY
H
V
V
H
T
H
H
H
H
V
V
V
V
RX
RY
Scattering matrix
S
S   vv
 S hv
S vh 

S hh 
CPD Filter
Co‐polarized phase difference (CPD), defined as phase difference between complex HH and VV channels, can potentially distinguish oil spills from other features found in the radar images of sea surface. References:
M. Migliaccio, F. Nunziata, A. Gambardella, “On The Copolarised Phase Difference for Oil Spill Observation”, Int. Journal of Remote Sensing, vol. 30, n. 6, pp. 1587‐1602, 2009.
D. Velotto, M. Migliaccio, F. Nunziata, S. Lehner, “Dual‐Polarized TerraSAR‐X Data for Oil‐Spill Observation”. OceanSAR 2009: Workshop on SAR Ocean Remote Sensing. 7‐11 September 2009, Herrsching, Germany
Both authors: IEEE, TGARSS, 2010, 2011
Oil Spill Using Dual-pol Data
HH
VV
CPDStd  std ( HH   VV )  std ( )
Platforms
Platforms
Oil
Oil
2
2
 ( L  1 / 2)(1   ) L  )] (1   ) L
2
pdf  ; L  

2 F1 ([ L ,1]; [1 / 2 ];  )
2 L 1 / 2
2
2   ( L )(1   )
Wind Shadow
Oil
Oil
Platform
Amplitude image
Platform
CPDStd image
 [deg]
[Ref] D. Velotto et al, “Dual‐polarized TerraSAR‐X data for oil‐spill observation”, IEEE TGRS, 2011. Oil Spill in Strait of Kerch
TerraSAR-X Stripmap
16 November 2007, 3:52 UTC.
Dual polarisation
( HH / VV / | HH – VV | )
Kerch
10 km
Oil Spill Strait of Kerch VV Polarisation
AZOV SEA
UKRAINE
KERCH
KERCH STRAIT
PORT KAVKAZ
B
A
BLACK SEA
10 km
DLR.de • Chart 16
> Lecture > Author • Document > Date
TerraSAR X CPD Filter
[Ref] D. Velotto et al,
“Dual‐polarized TerraSAR‐X data for oil‐spill observation”, IEEE TGRS, 2011. Broadening of CPD over Oil
due to scattering effects
DLR.de • Chart 17
> Lecture > Author • Document > Date
Oil Spill Kerch Strait: Modulus, CPD Filter, Correlation
Oil Spill Campaign in the Straits of Florida
NSUOC
GPS
Retractable
mount
Sonar
CTD
ADCP
TerraSAR-X Image
a
Sept. 25, 2009 23:13UTC
Ft. Lauderdale Florida Coast
wake 1
Features
a
• Ship wakes (1, 2, 3)
• Frontal interface (a)
• Surfactant releases (b, c)
• Natural slick (d)
b
d
wake 2
c
b
wake 3
Ship Wake
c
Natural Slick
Artificial Slick (Menhaden Fish Oil)
Earth Observation Center
EU DOLPHIN: Dual Cross Pol HH/HV Campaign with Bundespolzei See
Helgoland
Kontrol
Boot
Buoy
Düne
Beiboot
Bayreuth (66m)
TS‐X 2013.04.15 dual‐pol HH/HV
Slant Range Projektion
23 / xxx
Conclusions:
•CPD Filters on Dual polarization SAR helps to distinguish oil spills and seeps from look alikes
•NRT Dual Co‐Pol Services for TerraSAR to be installed at the Ground Station
• Visibility of the fine ocean structure in SAR depends on local weather conditions as well as presence of surfactants
•Campaigns supports the view that under certain conditions the three‐dimensional structure of the upper layer of the ocean can be inferred from the high‐resolution SAR imagery
•Cross Pol Mode improves wake and ship detection •TerrasaR to be added to CSN, several warnings a day at Bundespolizei See
Danke für Ihre
Aufmerksamkeit
Montara Oil Platform
Timor Sea, 2009
Cargo Rena – Case Study Co Pol‐ TerraSAR
Co-registered and Colour coded composite R: VV G: HH B:VV-HH
TD-X 2012-01-15 17:36UTC HH polarization
TS-X 2011-10-19 17:36UTC VV polarization
Internal Waves
Campaign mit AGeoBW
Geplante Zusammenarbeit NURC, WTD 71
Gannet Alpha Oil spill
Forties Field
Gannet Alpha
On 14th August 2011 an oil leak from the
Gannet Alpha platform in North Sea Britain’s
water was found by Marine Scotland. It has
been classified as “significant spill” and
Britain’s worst oil spill for over a decade.
TS-X ScanSAR VV-pol North Sea
08-17 17:37 UTC
Time: 2011-
TS-X and WV-2 Detection near Bandar Abbas Jun 27, 2009
semi automatic oil spill detection
Source: Ship Page 29
Weathering Processes of Oil Spilled at Sea and SAR Interpretation
ߣ௥
ߠ
Bragg Scattering & Wind
driven Capillary Waves
Evaporation
Wind
Oxidation
from 0.5 – 10 cm
Spreading
Spreading
Emulsification
Currents
Dissolution
Dispersion
Biodegradation
Surfactant layer < 0.1 ߤm
Sedimentation
Bragg scattering
20  θ  60
:
B 
r
2 sin θ
1.8   B  4.5
3.2   B  8.2
[cm]
at X-band (9.65 GHz)
at C-band (5.30 GHz)
TerraSAR-X Oil spill Detection Toolbox
TS-X Main
Directory
Read Metadata
Read and
Resample Image
Quick-look
generation
Calibration and
despeckling
Dark Area
detection
Features
Extraction
Classification
ROI selection
TS-ODT Core
No
Finish
Yes
Quicklook with
oil contour line
Save Output
text files
Neural Network - China oil spill study case
Folie 32
Institut für Methodik der Fernerkundung bzw. Earth
Deutsches
Fernerkundungsdatenzentrum
Observation
Center
32