New for Nortek instruments users
This page summarizes the new features, improvements and other changes that have been implemented in Echoview 16 which specifically affect the use of data from Nortek Signature echosounders.
Support for CTD-derived sound speed profiles
Echoview now supports the use of CTD-derived sound speed profiles with Nortek Signature data. This enhancement allows users to apply a variable sound speed profile—typically collected from a Conductivity-Temperature-Depth (CTD) instrument—via an ECS file.
Previously, Nortek Signature data always used a fixed sound speed for range and Sv calculations. Now, users can incorporate real-world CTD measurements for improved scientific accuracy.
When a sound speed profile is applied, Echoview uses it to:
- Update sample positioning (start and stop ranges) to reflect accurate sound travel times at different depths
- Adjust the calculation of Sv (volume backscattering strength) using the depth-dependent sound speed
This is especially useful for data collected in environments with strong variation in temperature and salinity—such as fjords, estuaries, or stratified coastal waters—where assuming a constant sound speed (e.g., 1500 m/s) could lead to errors in depth or backscatter estimates.
The CTD profile is specified using the CtdDepthProfile and SoundSpeedProfile settings in the ECS file.
For more information on how CTD profiles work in Echoview, see About CTD data and Using sound speed profile data.
See also: