Common calibration names

Common calibration names used in Calibration sources and ECS files.

Note: A default value is used when a setting's value is outside of the valid range.

Calibration setting name

Help file terminology

Default value

Decimal places

Units

Min

Max

AbsorptionCoefficient

Absorption co-efficient

0.01

dB per meter

100

CalibrationOffset

Calibration offset

When used for a TS to Sv or Sv to TS virtual variable refer to Choosing a calibration offset: Simrad Ex500, Simrad Ex60.

-99.9

99.9

Frequency

Kilohertz

0.01

10000

MajorAxis3dBBeamAngle

Major axis 3 dB Beam angle

This value can be used for:

Corrected schools analysis variables
Beam compensation of single targets detected in Echoview
3D Single targets graph beam rings
The Wedge_volume_sampled calculation (unless the WedgeVolumeBeamAngle is specified below)
The Motion correction (Dunford method) operator

Note: Pre-Echoview 5.0, MajorAxis3dBBeamAngle was a setting on the Calibration page of the Transducer Properties dialog box. As a result, this may have affected analysis results for some formats, particularly when the value in the data file used for the raw variable differed from the value entered for the Transducer Properties (and used for analysis calculations).

7.1

Degrees

359.99

MinorAxis3dBBeamAngle

Minor axis 3dB beam angle

This value can be used for:

Corrected schools analysis variables
Beam compensation of single targets detected in Echoview
3D Single targets graph beam rings
The Motion correction (Dunford method) operator

7.1

Degrees

359.99

TransmittedPulseLength

Transmitted pulse length

Milliseconds

0.001

SoundSpeed

Sound speed

1500

Meters per Second

1400

1700

TvgRangeCorrection

TVG Range Correction

The purpose of TVG range correction is to correct for the introduced errors from nominal TVG and apply TVG at the correct range, particularly for data collected at short ranges. If your data is located in the transition from near field to far field conditions (short ranges), then the application of TVG at the correct range becomes important. Using TVG range correction for Sv and TS data helps to minimize error for further calculations such as the estimation of biomass.

TVG range correction is also important in the choice of Echoview single target detection method for your data.

ECS example:

TvgRangeCorrection = None

Available TvgRangeCorrection values, that specify the TVG range correction algorithm applied to an acoustic variable, include:

TVG Range Correction algorithm		Affects data format?
TVG Range Correction algorithm		Ex500	Ex60	BioSonics	Kaijo	Other (HAC)
General algorithm applicable to Sv or TS	None	P	P	P	P
	BySamples	Wn telegrams TS & Sv	P	P	P	x
	PulseLength	Wn telegrams TS & Sv	P	P	P	x
	Ex500Forced	Wn telegrams TS & Sv	P	P	P	x
Variable specific algorithm applied as a default	SimradEx500	Wn telegrams Sv	Wn telegrams Sv	x	x	x
	SimradEx60	Wn telegrams Sv	Sv only	Sv only	P	x
	BioSonics	Wn telegrams Sv	Sv only	Sv only	P	x
	Kaijo	Wn telegrams Sv	Sv only	Sv only	P	x

Notes:

Some variables will use a variable-specific algorithm (default setting) as determined by the data format.
Pre-Echoview 5 EV files may have applied TVG range correction as a setting on the Calibration page or for some formats/variables the TVG range correction was applied on the Calibration 2 page (now deprecated).

The Calibration 2 page TVG range correction setting could toggle between two states. The default state (Checked) applied a variable-specific TVG range correction. The Unchecked state directed Echoview to not apply a TVG range correction.
HAC data - dependent on the original data source.

None

None
BySamples
PulseLength
Ex500Forced
SimradEx60
Biosonics
Kaijo
SinradEx500

TvgRangeCorrectionOffset

TVG Range Correction Offset

Specifies the number of samples for the BySamples TvgRangeCcorrection algorithm. See also TvgRangeCorrection.

Samples

-10000

10000

TwoWayBeamAngle

Two-way beam angle

-20.6

dB re 1 Steradians

-99

-1

BeamOffsets

Example:

BeamOffsets = 0.51 0.50 0.35 0.21

Represents the beam specific calibration values as follows:

Beam	Two-way beam angle
0	0.51
1	0.50
2	0.35
3	0.21

dB re 1 Steradians

-99

-1

WedgeVolumeBeamAngle

WedgeVolumeBeamAngle is specified when you want to override the MajorAxis3dBBeamAngle when specifying the across track beam angle in the Wedge volume sampled algorithm.

7.1

Degrees

359.99