Large offsets in position angle for HSC data

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#1

Hi all,

I’m planning an observing run for this fall with HSC, and we are considering using large offsets in position angle (say, PA=(0,180) or PA=(0,120,240)) for each of our observing blocks to reduce the effects of the CCDs with unavailable channels .

My concern is whether this will cause us problems in the data reduction. I’m currently using version 17 (last major release). Is there any reason to expect that the pipeline will have trouble combining exposures with large differences in position angle?

Thanks for any input!

#2

I wouldn’t expect any trouble, and I’d definitely encourage you to do rotational dithers, especially if you can’t do much in the way of positional dithers for some reason. While SSP observations are not taken with rotational dithers, there are no assumptions in the pipelines about that.

#3

The UH observations of the Cosmos field were taken with rotational dithering, and we processed them just fine.

#4

Great, thank you both!