Prepare directories and setting data¶

Once you downloaded your data, you need to create a directory for data reduction and setup data. In this section, 1) creating a directory for reduction and _mapper file, 2) setting Brighter-Fatter kernel, 3) creating links to reference catalog, 4) Set up the data of the transmission curve for HSC filters, 5) Y-band Stary Light are described. If you have installed hscpipe using a binary package, you complete those three steps just executing hscpipe/6.7/create-rootdir.sh. When you use HSC data analysis machine for open use (hanaco), you are also available the script installed in hanaco.

# Use create-rootdir.sh
# Assume reference catalog is in ~/astrometry_data/,
# ~/HSC as a directory for reduction and hscPipe package is under ~/opt
~/opt/hscpipe/6.7/create-rootdir.sh ~/HSC ~/astrometry_data/ps1_pv3_3pi_20170110

# On hanaco
/data/ana/hscpipe/6.7/create-rootdir.sh /data/[user]/HSC /data/ana/hscpipe/ps1_pv3_3pi_20170110

# /path/to/hscpipe/version/create-rootdir.sh [directory for reduction] [directory for reference catalog]
# The directory for create-rootdir.sh and the reference catalog in hanaco is fixed.
# ~/HSC/_mapper, link named ps1_pv3_3pi_20170110 in ~/HSC/ref_cats, and link named ~/HSC/CALIB/BFKERNEL/brighter_fatter_kernel.pkl are created.

If you do not use a binary package, you need to set one by one. The detailed ways are described below.

Creating a directory for reduction and _mapper file¶

_mapper file indicates which equipment is used.

Warning

The reduction dose not proceed without _mapper file.

# Setup environment variables with hscPipe setup command
# You need to do every login.
setup-hscpipe

# Create a directory for reduction (in case of ~/HSC)
mkdir ~/HSC
# Create _mapper file
echo 'lsst.obs.hsc.HscMapper' > ~/HSC/_mapper

Setting Brighter-Fatter kernel¶

For hscPipe 5 and 6, you need to copy the kernel which removes the brighter-fatter effect (whereby brighter stars are enlarged due to detector physics) under ~/HSC/CALIB. If you execute create-rootdir.sh included in binary package, this step has already been done. If you set the kernel manually, please follow the instruction below.

# Make BFKERNEL directory (you have to name “BFKERNEL”) under ~/HSC/CALIB
mkdir ~/HSC/CALIB/BFKERNEL

# There is brighter_fatter_kernel.pkl in $OBS_SUBARU_DIR/hsc/, so create link to it.
cd ~/HSC/CALIB/BFKERNEL
ln -s $OBS_SUBARU_DIR/hsc/brighter_fatter_kernel.pkl

Creating links to reference catalog for astrometry¶

In the CCD processing, the astrometric and photometric calibration are performed using reference catalog.

Note

While you need to execute setup astrometry_net_data command at every login for hscPipe4 or earlier, you just need to create a link below only once for hscPipe5 or later.

# Assume that catalog files are under ~/astrometry_data/.
# Create ref_cats directory (the directory name must be "ref_cats"!).
mkdir ~/HSC/ref_cats

# Move to ref_cats, and create link to reference catalog.
cd ~/HSC/ref_cats
ln -s ~/astrometry_data/ps1_pv3_3pi_20170110

Set up the data of the transmission curve for HSC filters¶

From hscPipe6, you have to set up the data of the transmission curve for HSC filters by yourself. To do this, type:

installTransmissionCurves.py ~/HSC

Y-band stray light¶

HSC has had some features known as “The Eye of Y” in the y-band images due to LEDs used in the instrument encoders(https://community.lsst.org/t/y-band-stray-light-correction-for-hsc/2517). From hscPipe 6, you need the stray light data to process Y-band images. Make directory ~/HSC/CALIB/STRAY_LIGHT and copy the stray light data from URL:http://tigress-web.princeton.edu/~pprice/strayLight/ in this directory.