New in Echoview 3.25
for users of data from Simrad echosounders
Note: Simrad is a subsidiary of Kongsberg. See also New for users of Kongsberg echosounders.
This page summarizes the new features, improvements and other changes that have been implemented in Echoview 3.25 which specifically affect the use of data from Simrad echosounders.
See also: New features in Echoview 3.25 for a description of changes that may affect you but are not specific to data from Simrad echosounders.
Range calculation error in Ex60 data
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. Every sample is offset from its correct position by one sample thickness. This is scheduled for correction in Echoview version 3.30.
The main effect of the range offset is to offset the range used to calculate time varied gain (TVG). This effect can be canceled by adding one sample to the applied TVG range correction. The documented recommendation and default value is 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 one sample thickness for TS data to account for the error in Echoview's range calculation.
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 calculation is corrected in Echoview 3.30.
Please contact Echoview Support if you would like further information.
Roll data
Echoview can now read roll data from SM2000 data files if it is logged there. This roll data is made available as a raw variable which can be applied to the multibeam data using the Multibeam roll at transducer operator.