Furuno FSV-30 (Research version) magnitudes and Sv equations

This transducer model is sometimes abbreviated to Furuno FSV-30R.

Echoview derives beamformed magnitude and Sv variables from Furuno FSV-30 (Research version) data files.

Magnitude beamformed pings

Magnitudes are reported as logged in the data file and represent incident or received sound pressure in µPa.

Sv beamformed pings

Where:

Pr

= 10log( pr) is the received (or incident) sound pressure (dB re μPa) read from the data file, where pr is the recorded sound pressure (μPa) in the low or high resolution data block of the data file.

SL
is the recorded source level (dB re μPa2) read from the data file.

g
is the recorded gain (μPa) in the low or high resolution TotalGain block of the data file.

r
is the range of the sample (m) read from the data file.

α
is the recorded absorption coefficient (dB/m) read from the data file. It is displayed as AbsorptionCoefficient on the Calibration page of the Variable Properties dialog box.

Ψ
is the equivalent two-way beam angle (steradians) see below. It is displayed as TwoWayBeamAngle on the Calibration page of the Variable Properties dialog box.
Note: Ψ dB = 10log ψ

c
is the recorded sound speed (m/s) read from the data file. It is displayed as SoundSpeed on the Calibration page of the Variable Properties dialog box.

τ
is the recorded transmission pulse duration (s) read from the data file.

gc
is the gain calibration correction and its value is 1 (dimensionless).

Ψc
is the equivalent two-way beam angle calibration correction and its value is 1 (dimensionless).

C
is the CalibrationOffset specified on the Calibration page of the Variable Properties dialog box, if any, 0 otherwise (dB)

Two-way beam angle

H-mode Sv data

Where MajorAxis3dbBeamAngle, MinorAxis3dbBeamAngle and MinorAxis3dbBeamAngleTransmit data are available in the data file, Echoview calculates the value for TwoWayBeamAngle and uses it to calculate the H-mode Sv value (see above).

When the aforementioned angle data is not available in the data file, Echoview uses the two-way beam angle recorded in the data file.

Two-way beam angle (steradians) = 1.13 x Bwtrv x MajorAxis3dbBeamAngle

where:

MajorAxis3dbBeamAngle, MinorAxis3dbBeamAngle and MinorAxis3dbBeamAngleTransmit are from the data file.

V-mode and S-mode data

Echoview uses the two-way beam angle recorded in the data file.

Pr	= 10log( pr) is the received (or incident) sound pressure (dB re μPa) read from the data file, where pr is the recorded sound pressure (μPa) in the low or high resolution data block of the data file.
SL	is the recorded source level (dB re μPa2) read from the data file.
g	is the recorded gain (μPa) in the low or high resolution TotalGain block of the data file.
r	is the range of the sample (m) read from the data file.
α	is the recorded absorption coefficient (dB/m) read from the data file. It is displayed as AbsorptionCoefficient on the Calibration page of the Variable Properties dialog box.
Ψ	is the equivalent two-way beam angle (steradians) see below. It is displayed as TwoWayBeamAngle on the Calibration page of the Variable Properties dialog box. Note: Ψ dB = 10log ψ
c	is the recorded sound speed (m/s) read from the data file. It is displayed as SoundSpeed on the Calibration page of the Variable Properties dialog box.
τ	is the recorded transmission pulse duration (s) read from the data file.
gc	is the gain calibration correction and its value is 1 (dimensionless).
Ψc	is the equivalent two-way beam angle calibration correction and its value is 1 (dimensionless).
C	is the CalibrationOffset specified on the Calibration page of the Variable Properties dialog box, if any, 0 otherwise (dB)