Sub-bottom and Bathymetry: Contacts aren’t just for Sidescan!

Chesapeake Times, Vol 8 | January 2022

One of the most powerful tools in the sidescan post processing arsenal of SonarWiz is the contact, an item which location and characteristics can be captured and saved. After these contacts are created on sidescan files they can be edited, measured, classified, and final reports can be built for your customer in a variety of formats. But did you know that users processing multibeam and sub-bottom data can also utilize these features?

For sub-bottom data, contacts can be placed in the digitizing view similarly to drawing reflectors. In a situation where the user doesn’t need to draw a complete horizon (for example identifying a buried pipe or boulder) a contact can be placed.

The created contact will contain all the standard meta data that its sidescan version would as well as offer the option to mensurate (except for shadow). In the Info at cursor section of the newly created contact will contain a new field labeled DBS (depth below seafloor) which will use the range to target field subtracted by the altitude to give the end user.

When processing bathymetry files, most users aren’t aware that you can capture areas of your 3D point cloud as contacts in the digitizing view! 

These special bathymetry contacts have their own report format that allows users to create 3D PDFs if your client does not have access to a 3D viewer. Just make sure to select “Adobe 3D PDF” in the Report Type down menu of the Contact Report Generator.

Each of these unique contact options contains the same properties of a sidescan contact, which allow users to recapture the images when edits or signal processing are applied, or when re-computing the position if navigation is adjusted.

To see one of these bathymetry contacts in a 3D viewer and many more great tips and tricks when using SonarWiz, check out our YouTube channel.

– Patrick Zynda, Support Engineer