15 Application of the Multi-sensor Fusion Method for Underwater Landscape Modeling
241
Instrumentation systems are simultaneously deployed on the mini-survey vessel:
• Interferometric system Geoswath+ NG for multibeam bathymetry
• Interferometric side scan sonar Geoswath+ NG for precisely geo-located mosaic
picture at 250 kHz
• Towed side scan sonar Klein 3900/5000
• Frequency 455 kHz/900 kHz
• Resolution 20 cm at 75 m
• Range max: 150 m for high resolution acoustic imagery
• Echo sounding Simrad ES60 high precision (scientific) for bathymetry/biocenoses/sedimentology
• Motion sensor Coda Octopus FS185+ for positioning and motion correction
• 2 D-GPS RTK Novatel for location and motion correction
• 2 D-GPS RTK Leica for land reference station and topography
• Automatic navigation and sailing system POSEIDON (on predefined survey lines)
• Data acquisition station
• Internet and VPN high rate (data transmission/reception)
• Mini-SVS Valeport profiler (Sound velocity profiles acquisition)
• Acquisition and processing data devices
• Geographic Information System—19” shelves available
• Professional divers. Video camera
Methods are operated simultaneously. Figure 15.1 shows principle of multi-sensors
acquisition.
To drive all these instruments we have developed a specific software, playing role
of an orchestra chef, named POSEIDON. This software pilots data synchronization,
acquisition, datation and positioning.
As precise 3D scan pictures of sea bottom could only be obtained with very high
accuracy at each step of data acquisition and processing, we have incorporated into
POSEIDON, GIS functionalities, processing algorithms and data fusion process.
15.3 Methods
In order to produce help to acoustic imagery interpretation, we have first developed
specific methods devoted to vegetation and sediment classification.
Principle of DIVA method (Detection & Investigation Vertical Acoustic), devoted to vegetation is based on single beam data automatic processing. The shape
of acoustic bottom impulse response from a scientific echo sounder is recorded simultaneously with centimetric GPS position. As sand and vegetation have different
acoustic signature shapes, we have developed a signal processing algorithm based on
discriminant analysis and energy level of the bottom reflected impulse response (Viala
et al. 2007). The DIVA method initially developed to Posidonia characterization is
also efficient for zostera or laminaria localization and cartography. Simultaneous
measurement using DIVA method should then increase the performance of multi
sensors fusion method.
241
Instrumentation systems are simultaneously deployed on the mini-survey vessel:
• Interferometric system Geoswath+ NG for multibeam bathymetry
• Interferometric side scan sonar Geoswath+ NG for precisely geo-located mosaic
picture at 250 kHz
• Towed side scan sonar Klein 3900/5000
• Frequency 455 kHz/900 kHz
• Resolution 20 cm at 75 m
• Range max: 150 m for high resolution acoustic imagery
• Echo sounding Simrad ES60 high precision (scientific) for bathymetry/biocenoses/sedimentology
• Motion sensor Coda Octopus FS185+ for positioning and motion correction
• 2 D-GPS RTK Novatel for location and motion correction
• 2 D-GPS RTK Leica for land reference station and topography
• Automatic navigation and sailing system POSEIDON (on predefined survey lines)
• Data acquisition station
• Internet and VPN high rate (data transmission/reception)
• Mini-SVS Valeport profiler (Sound velocity profiles acquisition)
• Acquisition and processing data devices
• Geographic Information System—19” shelves available
• Professional divers. Video camera
Methods are operated simultaneously. Figure 15.1 shows principle of multi-sensors
acquisition.
To drive all these instruments we have developed a specific software, playing role
of an orchestra chef, named POSEIDON. This software pilots data synchronization,
acquisition, datation and positioning.
As precise 3D scan pictures of sea bottom could only be obtained with very high
accuracy at each step of data acquisition and processing, we have incorporated into
POSEIDON, GIS functionalities, processing algorithms and data fusion process.
15.3 Methods
In order to produce help to acoustic imagery interpretation, we have first developed
specific methods devoted to vegetation and sediment classification.
Principle of DIVA method (Detection & Investigation Vertical Acoustic), devoted to vegetation is based on single beam data automatic processing. The shape
of acoustic bottom impulse response from a scientific echo sounder is recorded simultaneously with centimetric GPS position. As sand and vegetation have different
acoustic signature shapes, we have developed a signal processing algorithm based on
discriminant analysis and energy level of the bottom reflected impulse response (Viala
et al. 2007). The DIVA method initially developed to Posidonia characterization is
also efficient for zostera or laminaria localization and cartography. Simultaneous
measurement using DIVA method should then increase the performance of multi
sensors fusion method.