Calibration settings for Kongsberg EM systems data

This page describes the settings, necessary to an Echoview calculation, on the Calibration page of the Variable Properties dialog box for acoustic variables derived from EM systems (*.KMall, *.KMwcd) files and EM systems (*.all, *.wcd) files.

We recommend you assess the suitability of the settings available on the Calibration pages for each acoustic variable. Quantitative calculation/analysis requires calibrated data which is achieved using correct calibration setting values (rather than default values). An ECS file enables you to modify calibration settings for variables in a fileset.

Changes in calibration settings used for range calculations may shift ping data in the depth dimension but will not automatically adjust the position of regions and lines. You should review any existing regions and lines to ensure they are still valid. For more information refer to Range calculation effects on regions and lines.

Note: Data file values that have been used since the data was loaded or the ECS file was added, saved or removed are displayed in black text. Default values that have been used are displayed in orange text. Data file or ECS values that have been read but not used are displayed in grey text. Read About calibration settings for further information.

Calibration settings for Kongsberg EM systems data (*.KMall, *.KMwcd)

* .KMall and associated *.KMwcd files often record data with Kongsberg adjustments. When Echoview derives a raw variable futher data handling may be applied. For more information refer for Kongsberg EM system *.KMall data files.

Table legend:

Y	Setting is used in calculating data point values or ranges as indicated by the column heading.
	Setting is not used in calculating data point values (when green background) or ranges (when blue background) but may be used for other purposes, see Additional uses of Calibration settings
	Setting is not available for this variable

Variables from EM systems *.KMall data files

Setting	Data point values		Range
	Sv pings	Unspecified dB pings	All acoustic variables
Calibration page of Variable Properties dialog box
Frequency (kHz)
PulseDuration (ms)
SoundSpeed (m/s)			Y
TvgRangeCoefficient	Y

Calibration settings for Kongsberg EM 3002, EM 3002D and EM 710 data (*.all, *.wcd)

Unspecified dB pings

No calibration settings apply. A transducer can be selected in order to apply transducer geometry to the echogram. However, note that the 3dB beam angle setting is not used. Schools variables are not corrected for beam width. There is no correction for beam shape in 3D school detection.

Sv beamformed pings

EM 3002: Sv pings
EM 3002D: Sv pings, Sv pings (Head 2)
EM 710: Sv pings

A transducer can be selected in order to apply transducer geometry to the echogram. However, note that the 3dB beam angle setting is not used. Schools variables are not corrected for beam width. There is no correction for beam shape in 3D school detection.

Echoview uses the signal magnitudes stored in the data files and the Multibeam magnitudes to Sv algorithm to derive the Sv beamformed pings variable. This variable can utilize calibration settings for each beam (BeamOffsets) or apply a value that will be applied to all beams (CalibrationOffset). These settings can be set with an ECS file which must be added to a fileset.

Notes:

• When specifying per-beam calibration, it is good practice to verify the settings for the correct number of beams.
• Prior to Echoview 5 this format used the (deprecated) Echoview ASCII calibration file to specify per-beam calibration values.

See also

About transducer geometry
Kongsberg data files
Raw variables derived from Kongsberg data
About calibration settings
Entering calibration settings