Changes to EK60 and ES60 data support in Echoview 2.20

This page applies to people who were using Echoview 2.10 to analyze EK60 data and have moved to Echoview 2.20 or later.

Following information received from Simrad a number of changes were made in Echoview 2.20 to the interpretation of EK60 and ES60 raw data files. These changes are summarized below.

EK60 and ES60 raw data handling in Echoview 2.20 and later

Angular position data

Angular position variables from EK60 raw data were displayed and calculated incorrectly in Echoview 2.10 and should not have been used for any processing or analysis. The raw angles exported in version 2.10 were also incorrect. Angles and angular positions are being correctly interpreted and displayed in Echoview 2.20 and later.

Sounder-detected bottom

The sounder-detected bottom information was not being implemented correctly in Echoview 2.10 - the sounder draft was being included. This has been fixed in Echoview 2.20 and later.

Filter and TVG range corrections

In Echoview 2.10, EK500-specific filter corrections and a TVG range correction could be applied to EK60 data. These corrections are no longer applied in Echoview 2.20 and later.

Sample resolution

In Echoview 2.10 the sample resolution was a setting on the Calibration 2 page of the Variable Properties dialog box that affected calculations of Sv and TS. The sample resolution for the EK60 data file is now read from the file and applied internally. It no longer needs to be entered in Echoview 2.20 and later.

Wavelength

In Echoview 2.10 the Calibration page for Sv and TS variables had a Wavelength setting that was used to calculate TS and Sv values. In Echoview 2.25 and 3.00 wavelength was calculated from the entered frequency and a fixed nominal sound speed of 1470.6 m/s. In Echoview 3.10 wavelength is calculated using the frequency and sound speed entered on the Calibration page of the Variable properties dialog box.

Important notes for EK60 users moving from Echoview 2.10 to Echoview 2.20 or later

Some of the Calibration settings that could be entered in Echoview 2.10 will now be handled internally and will no longer appear on the Calibration pages. If you have been using Echoview 2.10 to process your EK60 data there are some settings that MUST have been entered correctly. If they were not, you may have to re-process your EV files in Echoview as they will change considerably. If you do open your EV files in Echoview 2.20 or later and notice changes in your echograms, it is most probably due to one of the settings below.

Pulse length and Bandwidth settings

The pulse length and bandwidth settings on the Calibration page of the Variable Properties dialog must be entered as "unknown" for all variables in EV files created in Echoview 2.10, otherwise EK500 corrections will be incorrectly applied.

Start sample range

Start sample range and Sample resolution settings appeared on the Calibration 2 page for Sv and TS variables in Echoview 2.10. This page no longer exists in Echoview.

Start sample range in 2.10 EV files should be set to zero. (Sample ranges that do not start at zero may not be handled correctly.)

Sample resolution

Note that for file created in Echoview 2.10 you MUST have the sample resolution on the Calibration 2 page correct for your analyses to be meaningful. To calculate this you will need to access the fixed sample interval (TimePerSample (secs)) from the EK60 and the sound speed that was entered in the EK60.

To calculate Sample resolution:

Sample resolution = (Sample interval * Sound speed)/2

If you did not enter this parameter correctly, you will have to recalibrate and re-analyze your data in v2.20 (or later). This calibration value is now read from the file and applied directly to the data.

TVG Range correction

Ensure that "Apply Simrad TVG range correction" on the Calibration 2 page is NOT checked for EK60 EV files in Echoview 2.10 or later.

Note:

All Echoview variables are INDEPENDENT. This information needs to be entered for each variable.

See also

Simrad data files
Calibration settings for Ex60 raw data
Calibration settings for EK500 telegrams logged with Ex60