1 Set up the EK80 for noise measurements

Low noise is a key factor for high quality and reliable measurements. The performance of the EK80 system will always be limited by different noise sources.

Context

Performing noise checks using the same transmission parameters will make it easier to compare results. Use this procedure to enter the transmission parameters for noise measurements.

Procedure

Set up all channels for normal operation.

Open the Operation menu.

Select Normal Operation.

The Normal Operation dialog box lists all the transmission parameters.The Normal Operation dialog box is only available when the EK80 system operates in Normal mode.

Set the transmission parameters for noise measurements.

Pulse Type:LFM (Linear Frequency Modulation) transmissions

Mode: Passive

If you set Mode to Passive, your EK80 system will no longer provide any information in the echogram(s).

Pulse Duration: 2.048 ms

Power: Maximum power

Ramping: Fast

Transducers not providing LFM transmissions, setup usin CW mode with the following parameter settings.

Pulse Type: CW (Continuous Wave) transmissions

Mode: Passive

Pulse Duration: 1.024 ms

Power: Maximum power

Ramping: Fast

An EC150-3C must be in echo sounder mode ES, in order to perform noise measurements.

Pulse Type: LFM (Linear Frequency Modulation) transmissions

Mode: Passive

Depth Cell Size: 2

Max Current Speed: 10 m/s

Power: Maximum power

Select the TVG values you want to use.

Open the Active menu.

Locate the TVG button.

Select TVG: Sv (20 Log)

Select Minimum Level: -70 dB.

Observe the Main menu on the left side of the screen.

Locate the Minimum Level button.

Select Minimum Level: -70 dB.

Select Range: 2000 m.