HiPS image creation from butler collection

Support
#1

Hi

We’re interested in generating HiPS images for some of our data and linking that to the UK RSP.

Is there some documentation somewhere to help with this?

I see there are some HiPS tasks in the stack but don’t know if/how that was used to generate the DP0.2 HiPS. And was this run on a butler collection etc.

Thanks
Mike

#2

We did use our own code to make the DP0.2 HiPS files.

There is some documentation here: HighResolutionHipsTask — LSST Science Pipelines

Note that today is a holiday in the US and @erykoff is on vacation this week.

#3

Thanks @timj, and sorry to disturb you holiday

On the doc page it says

“Note that this task only generates HiPS-compatible exposures, it does not generate a HiPS directory tree.”

I take this to mean it creates the highest resolution image(s) warped to the healpix pixels.

Is there then a further task to generate the different resolution levels or was the CDS software used? Probably one for @erykoff when they are back.

Cheers
Mike

(Tagging @raphaelshirley )

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#4

You correctly identified that the work was done in two phases - one to warp our coadds to the HEALPix grid, and then another to walk up the tree and generate the lower-resolution images.

We wrote our own code to do all of it.

I believe the second phase is handled by GenerateHipsTask in pipe_tasks/hips.py at main · lsst/pipe_tasks · GitHub but we’ll have to wait for @erykoff for instructions.

#5

Hi @erykoff, do you have any further instructions/notes for generating HiPS from a butler collection?

thanks
Mike

#6

Sorry for the delay, I was on vacation and then was in Chile for our meeting.

One thing that may be of note are the pipetask calls that we use in CI to run the HiPS generation, as in ci_hsc_gen3/pipeline.sh at main · lsst/ci_hsc_gen3 · GitHub

We have to have some special-case code (particularly build-high-resolution-hips-qg) because our workflow system doesn’t yet fully support HEALPix geometry. But this code tells the workflow system how to split things up. The pipeline is defined in ci_hsc_gen3/highres_hips.yaml at main · lsst/ci_hsc_gen3 · GitHub for this step. Finally you can generate the HiPS tree with the next task defined in ci_hsc_gen3/gen_hips.yaml at main · lsst/ci_hsc_gen3 · GitHub.

Those are settings for HSC in CI. For DP0.2 specifically, I am having trouble finding the configuration that I used for this run. Is this something you need?

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#7

Thanks @erykoff , hopefully it’s enough to get us started