I haven’t been able to find any information about error values related to roll, pitch, and heading for the Cube. Are those available somewhere?

Can you determine exactly what you are after?

I’m looking for the standard deviation values of the IMU output for body angles, body angle rates, or Euler angles/rates if the filter provides those too.

Not entirely sure what you’re asking here. Are you asking what accuracy the cube offers generally, or are you asking how to get the variances from ardupilot’s EKF?

If the former, it isn’t an easy answer. It depends on a lot of things. Assuming we’re using Ardupilot’s EKF, assuming the IMU has reached temperature, assuming it was calibrated at that temperature, assuming the compass is calibrated, assuming that the world magnetic model is accurate for the location (i.e. the system is measuring no external magnetic fields), assuming the GPS is either not in use (static scenario) or has a clear view of the sky (dynamic scenario), I would expect better than 0.5 degree accuracy on roll and pitch and 1 degree accuracy on heading.

If the latter, no part of the covariance matrix in ardupilot’s EKF is currently available in telemetry or logs to the best of my knowledge.

Thanks Jon, that was what I needed. Can you say if those accuracy values for roll, pitch, and heading are RMS values, standard deviation, maximum error, best estimate, etc…?

Exactly why is this information important?