6 Reducing the random errors in ADCP measurements

There will always be random noise in water velocity estimates. The random noise can be reduced by using the averaging the velocity estimates over a fixed number of pings. Use this function to reduce the random noise by using the Ping Average function.

Context

The average values are determined using a selected number of pings and the sliding average principle. Use the Ping Average function to specify how many pings you want to use. The averaging operation reduces the ensemble noise of a a factor of approximately √N, where N is number of averaged pings. Ping average represents the number of pings used to create these subsets of pings used to calculate the moving average.

Note

For scientific operations, select the Ping Average value according to survey requirements.

Procedure

Click inside one of the ADCP views.

Note

The changes you make are by default applied to all views in the current ADCP presentation.

Open the Active menu.

Select a Ping Average setting that fits you requirements.

To change the setting, move the cursor to either side of the button. Select the left side of the button to decrease the value. Select the right side of the button to increase the value. Select the middle of the button to open it. You can choose any of the predetermined options in the list.