System noise

Figure 1: System noise – here is an example of electronic noise that has been amplified above the threshold level. This noise is not acoustic in nature. It would also be present in ambient mode and visible with echosounder in ‘passive mode’. Always a good idea to operate your system in passive mode when you have a new or changed installation to ensure that your system noise (from the echosounder or the environment) is minimal or absent.

Figure 2. 120 kHz Simrad Ex60 data (Rhian Evans/IMAS), electrical system noise.

Figure 3. 120 kHz Simrad Ex60 data (Rhian Evans/IMAS), electrical system noise and intermittent acoustic noise.

Figure 4. 120 kHz Simrad Ex60 data (Rhian Evans/IMAS), system noise possible electrical.

See also

Examples of echogram interpretation
Noise, background objects and attenuated signal in Echoview