About the velocity measurement (ADCP) views
The EK80 system supports several different ADCP data measurements. Each type of ADCP measurement is shown in a separate view in the display presentation. Echo sounder information and ADCP information are provided in separate views and cannot be mixed.
Selecting presentation mode on the bottom bar
The bottom bar is located at the bottom of the display presentation and stretches from the left side to the right side. The bottom bar provides specific tabs to open selected views. When fitted with hardware for velocity measurements, the EK80 can be used in both normal echo sounder mode and in ADCP mode. The bottom bar provides separate tabs for velocity measurement (ADCP) and echogram views.
By means of the Presentation Modes dialog box you can change the order of these tabs, and you can add your own tabs.
By default, the views are arranged automatically in the presentation. You can change the physical size of any view. Click on the view border, hold the button depressed, then drag the border to create a smaller or larger rectangle. Note that the size of the other views are changed accordingly!
Supported velocity measurements (ADCP)
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.
Selecting which velocity measurement (ADCP) views to present
Use the ADCP View Settings dialog box to select the ADCP views you want to see. You can also define the parameters for these views. This includes horizontal axis units, labels, lines and ticks. These features are implemented to enhance the ADCP data presentation. The ADCP View Settings dialog box is located on the Active menu.
Setting lines and markers in ADCP views
The Lines page in the ADCP View Settings dialog box controls the horizontal and vertical lines used in the ADCP views. The ADCP View Settings dialog box is located on the Active menu.
Working with depth layers in ADCP views
Exploring velocities in different layers of the water column is done using depth layers. Layers are used to calculate various values from the echo data collected within a specific depth range in the water column.