HSC calibration data set¶

The HSC team provides a calibration data set reduced with hscPipe for each observing run. This service has started as a part of our standard data reduction service for HSC under development. You can use them for your data processing.

Note

Calibration data published prior to March 15, 2021 did not reflect BIAS and DARK frames in the creation of FLAT, FRINGE and SKY. Now, it has been replaced with the correct data. Effects of the correction on FLAT, FRINGE and SKY frames are typically less than 0.01%, which should be hardly a problem on data processing. If you need the previous data, please contact us at helpdesk_AT_hsc-software.mtk.nao.ac.jp.

Calibration data can be downloaded below:

CALIB with hscPipe 8.4; See also Summary figures of CALIB data

The directory tree is as follows:

CALIB_YYYYMMDD (YYYYMMDD is the starting date of a run, like CALIB_20191023)
|--BIAS    # BIAS data
| └--[dateObs]
|   └--NONE
|     └--BIAS-[dateObs]-[ccd].fits
|--DARK    # DARK data
| └--[dateObs]
|   └--NONE
|     └--DARK-[dateObs]-[ccd].fits
|--FLAT    # FLAT data
| └--[dateObs]
|   └--[filter]
|     └--FLAT-[dateObs]-[filter]-[ccd].fits
|--FRINGE  # FRINGE data for near-infrared images e.g., HSC-Y, NB0816 and so on
| └--[dateObs]
|   └--[filter]
|     └--FRINGE-[dateObs]-[filter]-[ccd].fits
└--SKY     # SKY data
  └--[dateObs]
   └--[filter]
     └--SKY-[dateObs]-[filter]-[ccd].fits

BIAS, DARK, and FLAT data are generated from the visits listed at https://subarutelescope.org/Observing/Instruments/HSC/calib_data.html

FRINGE and SKY images are generated from the scientific images taken in each run. We use all the scientific images in each run with exposure time longer than 30 sec to generate FRINGE and SKY images. We note that it is ideal to generate FRINGE and SKY images by more than 50 scientific images, however, one observer’s images are not always enough for them.

Once you have download the calib images, register them at your directory for calibration data, e.g.,

ingestCalibs.py ~/HSC --calib ~/HSC/CALIB/ [path to your downloaded calib images]/BIAS/*/*/BIAS-*.fits --mode=link --validity 30
# Here, your directory for data processing = ~/HSC,
# and your directory for calibration data = ~/HSC/CALIB