New in Echoview 3.20
for users of data from Simrad echosounders

This page summarizes the new features, improvements and other changes that have been implemented in Echoview 3.20 which specifically affect the use of data from Simrad echosounders.

See also:   New features in Echoview 3.20 for a description of changes that may affect you but are not specific to data from Simrad echosounders.

General

Support for up to 9 transducers in Ex500 style telegrams

Echoview now supports up to 9 transducers (the previous limit was 4). The transducer number is encoded in the name of the raw variables.

Ex60

Heading variables derived from Ex60 .raw, .ek60 and .ek6 files

Echoview can now derive a heading variable from Ex60 .raw files and Ex60 .ek60 or .ek6 files to which heading data was logged. Echoview will not use heading data from these variables by default and will instead infer heading from a platform's cruise track (this is consistent with previous versions of Echoview). If you want Echoview to use heading data from a heading variable, you must select the variable as the Heading source on the Attitude_page of the Platform Properties dialog box.

See About heading data for details on what is affected by heading data.

Support for multiplexed Ex60 .raw files

Support for multiplexed Ex60 .raw files (for a specific application of the National Marine Fisheries Service) has been added to Echoview and Echocheck. Please contact SonarData for more information about this project.

Update to recommended TVG range correction

It has been confirmed by Simrad that Echoview version 3.20 and earlier versions have misinterpreted the range of the first sample in each ping. This means that every sample is offset from its correct position by one sample thickness. The range offset is scheduled to be fixed in Echoview version 3.30.

The main effect of the range offset is to offset the range used to calculate TVG. This effect can be canceled by adding one sample to the applied TVG range correction. The previous recommendation was a TVG range correction of two times the sample thickness for Sv data and zero for TS data. This should be changed to three times the sample thickness for Sv data and 1 sample thickness for TS data.

These changes will guarantee that the Sv and TS data points will have the correct TVG applied and therefore the correct Sv and TS values. The data points will still be offset in range by one sample thickness, until the range offset is fixed. Please contact Echoview Support if you would like further information.

SM2000 FR

Heading variables derived from SM2000 data files

Echoview can now derive a heading variable from SM2000 data files to which heading data was logged. Echoview will not use heading data from these variables by default and will instead infer heading from a platform's cruise track (this is consistent with previous versions of Echoview). If you want Echoview to use heading data from a heading variable, you must select the variable as the Heading source on the Attitude_page of the Platform Properties dialog box.

See: About heading data for details on what is affected by heading data.

Checking SM2000 FR data files with Echocheck

Echocheck will scan data files for certain corruptions and problems that could cause Echoview to fail. We recommend running Echocheck on any data files that cause problems with Echoview. It will process the following types of data files:

• .bfm or .bmf beamformed data files recorded using Simrad SM2000 FR echosounders

• .raw files recorded Simrad SM2000 FR echosounders

• .nnn files for multibeam data logged from an SM2000 FR echosounder (nnn are three digits)

Sv data

Sv variables are now available derived from the data in SM2000 FR data files. These must be calibrated before any quantitative analysis. See Raw variables derived from Simrad data files for further information.