LSSTCam rotational dithers

I am trying to find a reference that explains what the rotational dither pattern is expected to be in the cadence simulation baselines. I think it’s either the LSSTCam rotation angle is changed every filter change or it’s set nightly. I am not sure. I have been finding it difficult to find a reference that says what the scheduler is doing for the rotation angle that I can cite. Any help would be much appreciated.

Thanks ,


Right, it’s probably not documented anywhere well because I hate thinking about the camera rotator. Currently, we set a random goal rotTelPos value per night, between -80,80 degrees for most things and between -75,75 for the DDFs. But, once a rotTelPos value is used for an initial pointing in a pair, the second visit in the pair will try to match rotSkyPos. That second visit should have a rotTelPos pretty close to the nightly value, but should be different. And then there’s some simple logic for what to fall back to if things have rotated out of rotator limits.

If nothing else you can cite the code itself: lsst-sims/sims_featureScheduler_runs3.3: DOI

1 Like