Page Comparison

...

Introduction

This section contains the documentation on how to import, display and process Water Column Data from Multibeam echo sounders. All the operations are performed from a folder of schema type Multibeam in a Geocap Seafloor project.

...

The Multibeam folder menu with the water column tools

Typical workflow

1. Before loading the water column data the survey line must have an entry in the project. This means the depth data for the same survey line first must be imported by the command Import Multibeam Sonar Data.
2. The import of water column data is done with the command xx. Import Multibeam Water Column dataData. The import can be time consuming dependent on the size of the file.
3. To visualize the water column data, use the command xx. Multibeam Display Water Column dataSwath. This will display both the swath and optionally the alongtrack of the water column data. This command exist on both the Multibeam schema type folder and the Multibeam Survey schema type folder.
4. To convert the water column swath data to point cloud data, use the command xx. Multibeam Extract Water Column dataPoints. This command will extract features and filter away much of the noise in the swaths.
5. To visualize the extracted point cloud data, use the command xx. Multibeam Display Water Column dataPoints.

Import Multibeam Water Column Data

This command will import water column data to Multibeam Survey type folders already loaded in the Multibeam type folder.

The Import Multibeam Water Column Data dialog

The content of the menu

The upper part of the menu shows the name of the project and folder the command is activated from.

...

The Display Water Column Swath dialog

Display Water Column Swath

This command is executed from folders with schema type Multibeam and will display the water column data (swath) from the selected dataset. The command can also be opened directly from a Multibeam Survey line.

The content of the menu

The upper part of the menu shows the name of the project and folder the command is activated from.

...

The Water Column Survey Line part

When opening the command from a Multibeam Survey line this part of the menu is missing.

• The pulldown menu will show survey lines containing water column data. The dataset item in the survey line is named Water Column.When opening the command from a Multibeam Survey line this part of the menu is missing. Click the Execute button to activate the display. 
• When a survey line is displayed, the Display Water Column Swath icon (Image Added) will appear in front of the name:
  
  Image Added

• Keep graphics:  When this option is clicked it is possibel to select a new survey line to display and keep the graphics of the previous.
   The pulldown will show all the survey lines which are displayed when the Keep graphics is turned on. 

Image Added

• Clicking the Image Added button will remove all water column displays in the actual folder.

The Across part

• Across: The check box allows for showing the across line from the water column cube. The across line is also called the Swath.
• Ping No : The slider allows for moving the swath along the survey line. The slider can be dragged by the mouse, or when the graphic slider item is clicked, also the keyboard's arrow left and arrow right keys can be used for the navigation. The actual ping number in the box on the right hand side of the slider, shows the ping number in the brick cube. By clicking the small arrows to the right it is possible to change the view.
• Step: This is the step number for how many pings to jump when navigating the swath.

...

The Extract Water Column Points dialog

Extract Water Column Points

This command is executed from folders with schema type Multibeam and will extract the content of water column data (swath) as point cloud data sets. An area filter can be applied to extract data inside a specific geographic area only, and not for the whole survey line. 

The content of the menu

The upper part of the menu shows the name of the project and folder the command is activated from.

...

The Display Water Column Points dialog

Display Water Column Points

This command is executed from folders with schema type Multibeam and is used to display Water Column Points from the selected datasets. 

The content of the menu

The upper part of the menu shows the name of the project and folder the command is activated from.

...