Infrastructure inspection

1. Sonar-lidar mapping
of harbor facilities:
concept, payload & method
CHC 2020|Canadian Hydrographic Conference
from February 24th to February 27th, 2020
Médoune Ndir
en partenariat avec le ministère de l'économie
et de l'innovation
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2. Outline
• Digital twin
• Survey platform
• Payloads (integration, calibration & QA)
• Data capture and processing
• Deliverables
• Conclusion
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3. Digital Twin?
➢ Virtual replica fed by spatio-temporal data sources
➢ The data makes the replica evolve as it ages.
• Datasets (position, shape, state, motion, time) are
collected by measurements sensors.
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4. Mapping
3D representation of a
transformer station
3D representation of a dam reservoir
3D representation of a bridge
3D representation of a shore platform
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5. Port Mapping
Annual transit:
• + 80 destinations worldwide
• 28 M tons of cargo
• 130 000 cruisers
Facilities:
➢ Maritime and railway station
➢ Terminals
➢ 18 km of linear
➢ 470 wharf boxes
➢ 1161 bollards
➢ 14 embankment areas
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6. Vessel platform
• F.-J. Saucier (traditional SSV);
➢ Equipped cabin (workstations)
➢ Designed deck (PNT sensors)
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F.J. Saucier
Lenght (m) = 8.2 Width (m) = 2.7 Draft (m) = 0,7

7. Data capture sensors
(payloads)
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Frequency : 450 kHz (or multifreq.)
Beams : 256
Depth resolution : 3 mm
Beamwidth (450 kHz) : 0.45°x 0.45°
Density : 150 pt/m2
R2 Sonic 2026
Reson SeaBat 7125
SV2
Frequency : 200 / 400 kHz
Beams: 512
Depth resolution : 6 mm
Beamwidth (400 kHz) : 0.45°x 1°
Density : 300 pt/m2
nsonification scheme
Wavelenght : 1500 nm
Measurement rate (pts/s): 250 000 to 1.016 M
Range resolution: 1 mm or less (reflectivity)
Beam width : 0.03°
Density : 2500 à 25000pt/m2
Z&F Profiler
9012A
Scanline scheme

8. Data capture sensors
(payloads)
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Hydrins iXBlue
AsteRx-U
Septentrio
Data:
Attitude angles: Rolling, Pitching and Yawing
Translation: Heave
Data:
Speed, Position and Time
AML Base-X
Data:
Sound speed, pressure

9. Guidelines
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Guidelines NCHRP: US transportation research board

10. Integration
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Computer and acquisition controller

11. Calibration (offsets)
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12. Calibration (boresights)
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13. Boresight assesment
(lidar)
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Before adjustment After adjustment

14. Boresight assesment
(sonar)
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Before adjustment
After adjustment

15. Data capture & processing
(real-time)
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16. Data capture
(field work)
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17. Raw data
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Mean duration: 6 days
Capture time: 8h
Storage: 100 Go
Footprints: +500M

18. TPU data for processed
Mbes (RTK solution)
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Horizontal uncertainty
Vertical uncertainty

19. RMS data for processed
lidar (RTK solution)
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Absolute accuracy
-0.250
-0.200
-0.150
-0.100
-0.050
0.000
0.050
0.100
0.150
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Deviations
Targets
Spherical target 3D deviations
in relation to the ground truth
DN DE DH
North(m) East(m) Up(m)
0.04 0.01 0.02

20. Processed data
Lidar+Mbes
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Intensity and backscatter

21. Analysis and monitoring
of warping
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Theoretical
stake-out
Actual
Position
Retreat
Forwardness

22. Analysis and
monitoring of warping
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Thematic map of deformations

23. Degradation analysis
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24. Conclusion
• Capture and processing
– High resolution data
– Continuous underwater and above surface wharf scanning
– Added value (QA, by-products, Data GIS-cloud sharing)
– Interpretation products
• Applications
– Prediction models
– Warping monitoring
– Dredging
– Environmental Risks
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