Uncertainty Assessment of Wave Elevation Field Measurement Using a Depth Camera

The present study suggests a methodology for acquiring wave elevation fields using a depth camera sensor, with assessment results for the test uncertainty. The depth camera module of an Azure Kinect is calibrated using marker arrays on the optic table, to obtain a polynomial mapping function between the pixel-wise and physical position. For installation of the depth camera in a wave channel, the system is aligned using the built-in inertial measurement unit of Azure Kinect to be perpendicular to the calm water surface. The systematic and random standard uncertainties were evaluated from the analysis of calibration and repeated tests, respectively. The wave height measurement results for the depth camera were compared to those for the capacitance-type and ultrasonic wave height gauges. The test uncertainty of the depth camera increased in large wave stiffness conditions, where the time-of-flight sensor has a disadvantage in measurement.

Automated summary

The study presents a method for using a depth camera sensor to acquire wave elevation fields and assesses the test uncertainty. The depth camera module of an Azure Kinect is calibrated using marker arrays to establish a mapping function between the pixel-wise and physical position. The depth camera is aligned using the built-in inertial measurement unit to be perpendicular to the calm water surface. The systematic and random standard uncertainties are evaluated through calibration and repeated tests, and the wave height measurement results are compared with other gauges.