Exporting single beam Sv, TS, angular position data to the ICES SONAR-netCDF4 Format (*.nc)

Echoview supports the export of single beam Sv, TS and/or angular position variable data and supported time series data to the ICES SONAR-netCDF4 file format using Type 5 equations. Where a position and/or a heading variable are used by the platform, GPS and heading data will also be written to the file format. Heave, pitch and roll are not currently supported.

The output *.nc file may be added to a fileset.

Export via Echogram menu

Exports a single variable type from single beam Sv, TS or angular position data.

1. Open an echogram of a supported variable type.
2. On the Echogram menu, select Export, To ICES netCDF4 Format ...
3. On the Export to ICES netCDF4 Format dialog box enter a file name.
4. Click Save.

Measurement - ICES SONAR-netCDF4 exporter

Exports a single variable or multiple supported variables, where multiple variables are supported operands of the Measurement - ICES SONAR-netCDF4 exporter.

1. On the Dataflow Toolbox select the exporter Measurement - ICES SONAR-netCDF4, drag and drop on to the Dataflow window.
2. On the Dataflow window, select the Measurement - ICES SONAR-netCDF4 exporter object, right-click and on the Shortcut menu select Exporter Properties.
3. On the Operands tab, specify a single supported or multiple supported operands.
4. On the Measurement - ICES SONAR-netCDF4 tab, specify the range of pings for export.
5. Click OK.
6. Double-click the Measurement - ICES SONAR-netCDF4 exporter object.
7. On the Export to ICES netCDF4 Format dialog box enter a file name.
8. Click Save.

Notes:

• On the Export Progress dialog box you can use the Cancel export button. This will stop the export and delete the last partial *.nc file.
• When the export or exporter does not output a file, a diagnostic message may have been sent to the Messages dialog box. See also the Support details.

ICES SONAR-netCDF4 Format *.nc

Echoview exports single beam ping data such that it conforms to the ICES SONAR-netCDF4 (version 2) document. Echoview writes a selected variable's values or multiple variables' values for Sv and/or TS and/or angular position data types to the output file.

Echoview uses the Type 5 conversion, which the SONAR-netCDF4 convention document comments "is intended for sonars for which the manufacturer computes standard TS and Sv values as defined in MacLennan et al. (2002)." Where a derived angular position variable is available, Echoview uses the methods described in Chapter 6. Split-aperture beams and subsection 6.1 Angles stored in file to output angular position values to the *.nc file.

The ICES SONAR-netCDF4 convention specifies data obligations for elements of the file format and describes the handling for missing data. Data obligation options include:

• Mandatory
• Mandatory if applicable or available
• Recommended
• Optional

Where an element is 'Mandatory' and a value is available, the value is output to the *.nc file.

Where an element is 'Mandatory', or the element is 'Mandatory if applicable or available' and it is applicable, and the value is unavailable, a default Echoview calibration value is output for the element.

For elements that are 'Optional', 'Recommended', or 'Mandatory if applicable or available' and it is not applicable, Echoview outputs an element value of '+NaN'.

Notes:

• Refer to further Support details
• See also COM Scripting: EvVariableAcoustic.ExportICESSONARNetCDF4, EvVariableVirtual.ExportICESSONARNetCDF4 for one single beam variable export.
• EvFile,Exporters, EvExporter.Export, EvExporter.ExportType, and enum eTypeIcesNetcdf = 19 support a pre-configured Measurements - ICES SONAR-netCDF4 exporter that allows multiple single beam operands on the Dataflow window.

See also

Exporting in Echoview
About exporting data
Export file formats
About exporting measurement data