Patch Tests in SonarWiz
Chesapeake Times Vol 22 | July 2025
SonarWiz has many tools for processing bathymetry data. As many of you know when you are processing bathymetry a lot of times you have to perform a calibration test or patch test on your bathymetry data set.
A patch test is a systematic approach used for calibrating these sensors that aid in bathymetry data acquisition. There are three main sensors needed to map the bathymetry of the seafloor positioning system, a motion and attitude sensor and a Multibeam Sonar.
The purpose of the calibration is to correct for systematic errors created between the position system, the attitude sensor and the Multibeam Transducer. The test to solve, oftentimes unavoidable errors due to misalignment between the motion sensor and the other sensors.
To access the patch testing utility you will find it on the bathymetry tab under the patch testing dropdown menu.
One of the first improvements that we’ve made to the patch testing is the order in which the patch testing steps appear. In older versions of SonarWiz the patch testing drop down menu was out of order. We have now updated the menu reflect the order in which patch testing should be completed.
To learn more about Patch Testing in SonarWiz check out our Quick Start Guides for Bathymetry processing found here Quick Start Guides.
The next feature I want to shine light on is the new Patch Test Report. Often times when Hydrographic Data is handed over, a quality control report must be completed as well. This can require the survey team to provide information on sensor calibration.
SonarWiz now offers the option to create a report demonstrating the calibration values and offsets for QC and deliverables. The Bathy Patch Test Report combines the patch test calibration images into a stacked result. This is available after you have completed all 4 parts of the Patch Test process.
To create a Bathy Patch Test Report:
1. Open the Patch Test Calibration tool
2. After the calibration is completed, click the Capture Image button on the Patch Test Calibration tool.
3. Repeat Step 1 and Step 2 for each of Time Calibration, Pitch Calibration , Roll Calibration and Heading Calibration.
4. Select Post Processing | Export | Project Reports | Bathy Patch Test Report to generate the final image
The report will be stored in your SonarWiz project directory inside the Bathy folder.
The next new feature or setting we have added to the patch testing tool allows the user to adjust the width of the profile drawn in the map window. To find this setting look for the Settings button inside the Patch Test dialog, and in the Patch Test App Settings window, there is a slider bar that adjusts the line thickness, as well as new Area Multiplier.
As I mentioned before In the Patch test, the user draws a profile across the data in the map window. This new feature allows the user and the tool to capture more points left and right of the line drawn, the setting allows the user to choose how many points are accepted into the test, eliminating flyers and smooths out a little of the uncertainty.
These new features and other new additions and fixes to SonarWiz come from our Customer’s suggestions and reports. If you know of a new feature that would make your processing workflow easier or you have found a part of SonarWiz not working, we would love to hear from you.