1 Selecting which velocity measurement (ADCP) views to present

The EK80 system supports several different ADCP data measurements. Each type of ADCP measurement is shown in a separate view in the display presentation. To select which velocity measurement (ADCP) views you want to see, use the View Selection page.

Context

Use the ADCP View Settings dialog box to select the ADCP views you want to see. The View Selection page allows you to choose which views to present, and how to organize them. The ADCP View Settings dialog box is located on the Active menu.

Vessel Velocity

The Vessel Velocity views display water velocities relative to the vessel. The views display water velocity in fore/aft and port/starboard direction as well as down towards the seafloor. Vessel speed is displayed separately.

Geo Velocity

The Geo Velocity views display water velocity relative to earth coordinates, i.e. water current velocity. The water current velocity is displayed in the cardinal directions (north-south, east-west), as well as velocity down towards the bottom. Water current speed is displayed in a separate view.

Beam Velocity

The Beam Velocity views display the water velocity along the beam directions. The water is either moving towards or away from the ADCP transducer at the same angle as the vertical orientation of the beam. The Beam Velocity views offers one presentation for each beam.

Backscatter

The Backscatter views present the echo intensity in echograms. There is one Backscatter view for each of the ADCP beams. Backscatter

Correlation

The Correlation views display a measure of the similarity between the received echoes. Correlation is a measure of data quality.

Error Velocity

Error velocity is the difference between two estimates of the vertical velocity. It is an important means to evaluate the data quality. Error velocity will show the magnitude of the errors, not the source.

Percent Good

The Percent Good view displays the percentage of pings which has passed a set of defined quality criteria. The rejection criteria include low correlation and large error velocity. The default threshold is defined in the ADCP Editing dialog box.

Procedure

Open the Active menu.

Select ADCP View Settings to open the dialog box.

Select View Selection to open the page.

Scroll the list of available views.

Check the box for each view you would like to present.

Select view orientation.

Select Horizontal to examine data over a certain period of time or distance.

Horizontal orientation mode arranges the views adjacent to each other horizontally. This is a useful presentation mode if you want to see ADCP data over a longer period of time or distance.

Select Vertical to observe the beams in comparison to each other, or to observe the same phenomenon in several beams.

Vertical orientation mode arranges the views adjacent to each other vertically. This is a useful presentation mode if you want to see snapshots of the complete water column in the four beams adjacent to each other.

Select Apply to display the changes you have made

Select OK to save the selected setting and close the dialog box.