visea-das survey toolbox & plume detection toolbox (introduction) jeroen aardoom aqua vision bv
TRANSCRIPT
ViSea-DAS Survey Toolbox &
Plume Detection Toolbox(Introduction)
Jeroen AardoomAqua Vision BV
Theoretical introduction
Practical data acquisition & calibration
ADCP measures:water velocity
ADCP measures:water velocity
ADCP measures:water velocity
ADCP measures:Relative Backscatter(echo strength)
ADCP measures:Relative Backscatter
Provides:spatial overview
ADCP measures:Relative Backscatter
Provides:spatial overview
ADCP measures:Relative Backscatter
Provides:spatial overview3-D
ADCP measures:Relative Backscatter
Provides:spatial 3D overview
Disadvantage:qualitative, no SSC (mg/l)
The Challenge:Quantify SSC, in Real-Time
Correct for signal losses:range&instrument normalizationwater absorptionsediment absorption
The working equation (Deines)
Sv normalized backscatter [dB]
C constant [dB]
TT temperature of the transducer [°K]
R slant range along the beam [m]
L transmit pulse length [m]
PT transmit power [W]
aw water absorption [dB/m]
as particle attenuation [dB/m]
Kc RSSI scale factor [dB/count]
E echo intensity [count]
Er received noise [count]
)()(log102
10 rcsw
T
Tv EEKR
LP
RTCS
VISEA-DAS Survey & Plume Detection Toolbox
VISEA-DAS Survey & Plume Detection Toolbox
Converts backscatter to SSCAcquires the data Real TimeAll data within 1 format & timestamp
VISEA-DAS Survey & Plume Detection Toolbox
ViSea-DAS
VISEA-DAS Survey & Plume Detection Toolbox
Survey & Plume Detection Toolbox
Correlation / calibration
OBSRaw data : Volt/Ampere
Is converted -> NTU water samples calibration -> SSC mg/l
ADCPRaw data : Relative Backscatter
Is converted -> Absolute Backscatterwater samples calibration -> SSC mg/l
Correlation / calibration
OBS (NTU) ADCP (IdB)Calibration
Onboard vessel / Real Time
CalibrationSensor Setup
3 Profile/calibration measurements
Cross section/Transects measurements
Typical sample/measuring scheme
Typical sample/measuring scheme
3 Profile/calibration measurements
Typical sample/measuring scheme
3 Profile/calibration measurements
Correlation / calibration
OBS (NTU) ADCP (IdB)Calibration
Onboard vessel / Real Time
Typical sample/measuring scheme
Every hour
3 Profile/calibration measurements
Typical sample/measuring scheme
3 Profile/calibration measurements
Correlation / calibration
Samples (mg/l)
OBS (NTU) ADCP (IdB)
Calibration Calibration
Cross validation
Post processing / analysis
Every hour
3 Profile measurements
Every hour
3 Profile measurements
• Transect measurements
Estuary - hourly calibration
