Let’s Count the Ways – Bathy Data Exports

Chesapeake Times, Vol 17 | April 2024

The traditional XYZ file from a bathymetry file can be done a few ways in SonarWiz once the survey data has been processed. Most of these exports can be found in the Post Processing tab > Export button, within the bathymetry section.

Which export is needed is up to you. For the basics of XYZ data points, there is the initial option of Export to XYZ. This dialog box has grown over the years, like many options in SonarWiz, to accommodate certain project requirements from our clients. But there is a lot there that is useful.

A good rule for this one is to start at the bottom option – to decide how much data you really want to export. ALL data (this could be a very large file), just the data seen on the main map, a single line of data, or data across survey lines (section data).

A simple survey above, just 200m x 70m will generate 3.2 million soundings (a file size of 88MB). One can imagine the data points created by a survey that spans a few kilometers.

Perhaps a better option might be to export the data from a gridded data set. Although not capturing every sounding point, a 1m or 2m grid along a survey section of a few kilometers will provide a decent result. From the survey data, grids can be created using 7 different algorithms, from mean and average to CUBE and Inverse Distance.

Throw in some contours and the result creates a nice image.

To get an XYZ file from the grid, use the tool Export Grid as…
Note: The size of the grid is defined from the input. For a requirement that needs a 2-meter grid, simply create a 2m grid from the raw bathymetry.

Of course, these tools simply take the CDF file and get into a format that makes your job easier. And we’re always adding new ones to help out.

But if you find yourself with time to spare, start with the CDF file and extract the data as needed. Use the tools CDF – CSV option.

Spreadsheet of data with 29 columns of data. The last two are the processed depth values.

If there are other ways needed for exporting your bathymetry data, let us know.