Are those some type of calibration targets on the side of coring drill?
this post was submitted on 30 Apr 2026
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These are aruco indices. Each represent a unique index. They are popularly used in robotics for all sorts of things. I'd imagine they serve some kind of recalibration purposes for this camera.
Since they know the exact position and rotation of the camera in relation to these markers, they can check if the markers move by small amounts, which would mean lens distortion.
I could be wrong though, since you would typically need quite a lot of them at different depths for a full camera calibration.
Actually maybe they're used to measure vibrations in the drill? The vibration data would be a lot smaller to download than a full video file, so they might process that info on site and send it back
They might also be AprilTags which look almost identical to Aruco markers but in either case they are so called fiducial markers.
They are typically used for pose estimation, which is the process of determining the relative position and rotation of the marker compared to one or more cameras.
The drill head is on a relatively long arm which can cause the kinematics (determining the head position by adding up angle sensors in the joints) to become a little imprecise.
Attaching markers to the head allows you to determine its position relative to the main body which you can use to verify/correct/supplement the position given by the kinematics.
In the end you know your drill head position with higher precision and certainty, which I would imagine is important when you want to take drill samples or shoot lasers at a tiny target.
While they could be used for camera calibration, ~~camera intrinsics usually don't change and~~ you'd typically have a calibration target with a much denser pattern on it. With only 3 measurement points you'd need to take hundreds of different pictures to get enough data for a good calibration.
While I believe you are correct and I don't think they are used for camera calibration, camera intrinsics are known to vary depending on external conditions. Cameras on autonomous ships need regular recalibration for instance.