Angular Displacement
There exists the polarization sky compass method used by insects. Two photodiodes with wavelength filters and polarizers are used to measure the orthogonal components of the polarization of a part of the sky to find the polarization alignment. Combined with the time of day and geographical location, this tells you where the sun is in the sky. The sun is then used as the absolute reference.

You don't need to find the sun if you just need an angular reference prior to turning. Just grab the polarization alignment before you start turning and then turn until the alignment changes to indicate that you turned the desired amount.

With static photodiodes, at least a third photodiode at 45 degrees to the first two required to differentiate the actual heading since the two orthogonal components from the first photodiodes are symmetrical so you won't be able to tell if you are aligned with one by 0 degrees or 180 degrees.

You can also rotate a single photodiode+polarizer or the polarizer in front of it. It may also help to be able point and aim at a section of the sky rather than always looking straight up for reason that become apparent if you read into the polarization pattern of the sky.

There are paper online that you can read about it. "Insects UV polarization sky compass" are some of the search terms you want.