1240826896 (J0835-4510, Vela)

Processing with VCSTools, with different phase slopes applied

> psrplot -g 1600x800 -N 4x1 -p G -j "F 512" -l pol=0-3 J0835-4510_n128_ch157-180.ar.T.newDM67.77203.D

Vela_200MHz_2021withUVcorr.png

> psrplot -g 1600x800 -N 4x1 -p G -j "F 512" -l pol=0-3 J0835-4510_n128_ch157-180.ar.T

Vela_200MHz_2019

> psrplot -g 1600x800 -N 4x1 -p G -j "F 512" -l pol=0-3 J0835-4510_n128_ch133-156.ar.T.newDM67.77203.D

Vela_185MHz_2021withUVcorr.png

> psrplot -g 1600x800 -N 4x1 -p G -j "F 512" -l pol=0-3 J0835-4510_n128_ch133-156.ar.T

Vela_185MHz_2019

Processing 1240826896 (Vela) with VCSBeam

Without any correction applied

With the latest (as of 5 Nov 2021) correction, which is to apply Xiang's correction to the "PP" element of the calibration Jones matrix:

Bash commands

# On Garrawarla
$ module use /pawsey/mwa/software/python3/modulefiles
$ module load vcsbeam
$ make_mwa_tied_array_beam -V
MWA Beamformer v2.18.1_e79c6bd
$ cd /astro/mwavcs/vcs/1240826896/vcsbeam
$ sbatch vcsbeam.sbatch

vcsbeam.sbatch

#!/bin/bash -l

#SBATCH --nodes=24
#SBATCH --ntasks-per-node=1
#SBATCH --cpus-per-task=1
#SBATCH --mem=370gb
#SBATCH --partition=gpuq
#SBATCH --gres=gpu:1
#SBATCH --time=01:00:00
#SBATCH --account=mwavcs
#SBATCH --export=NONE

module use /pawsey/mwa/software/python3/modulefiles
module load vcsbeam

srun -N 24 -n 24 make_mwa_tied_array_beam \
    -m /astro/mwavcs/vcs/1240826896/1240826896_metafits_ppds.fits \
    -b 1240826897 \
    -T 295 \
    -f 133 \
    -d /astro/mwavcs/vcs/1240826896/combined \
    -P pointings.txt \
    -c /astro/mwavcs/vcs/1240826896/cal/1240827912/vis/1240827912.metafits \
    -C /astro/mwavcs/vcs/1240826896/cal/1240827912/rts \
    -p -R NONE -U 0,0 -X

Post-processing steps:

Post-processing commands

$ /pawsey/mwa/singularity/dspsr/dspsr.sif dspsr -c 0.08940704866643866 -D 67.97 -b 128 -L 10 -A -K -cont -U 600 G0034_1240826896_08:35:20.61_-45:10:34.87_ch133-156_000?.fits
$ singularity run -B ~/.Xauthority /pawsey/mwa/singularity/psrchive_tempo2/psrchive_tempo2.sif psrplot -N 4x1 -p G -l pol=0-3 -j T -j "F 512" -g 1000x500 -D 2019-05-02-10\:08\:00_no_correction.png/png  2019-05-02-10\:08\:00.ar

This produces the following:

(Running pdmp on the resulting archive indicates that a better DM might be 67.814.)

With Xiang's correction applied to PP

Same steps as above, except that the beamforming command is:

vcsbeam.sbatch

#!/bin/bash -l

#SBATCH --nodes=24
#SBATCH --ntasks-per-node=1
#SBATCH --cpus-per-task=1
#SBATCH --mem=370gb
#SBATCH --partition=gpuq
#SBATCH --gres=gpu:1
#SBATCH --time=01:00:00
#SBATCH --account=mwavcs
#SBATCH --export=NONE

module use /pawsey/mwa/software/python3/modulefiles
module load vcsbeam

srun -N 24 -n 24 make_mwa_tied_array_beam \
    -m /astro/mwavcs/vcs/1240826896/1240826896_metafits_ppds.fits \
    -b 1240826897 \
    -T 295 \
    -f 133 \
    -d /astro/mwavcs/vcs/1240826896/combined \
    -P pointings.txt \
    -c /astro/mwavcs/vcs/1240826896/cal/1240827912/vis/1240827912.metafits \
    -C /astro/mwavcs/vcs/1240826896/cal/1240827912/rts \
    -p

Post-processing commands

$ /pawsey/mwa/singularity/dspsr/dspsr.sif dspsr -c 0.08940704866643866 -D 67.97 -b 128 -L 10 -A -K -cont -U 600 G0034_1240826896_08:35:20.61_-45:10:34.87_ch133-156_000?.fits
$ singularity run -B ~/.Xauthority /pawsey/mwa/singularity/psrchive_tempo2/psrchive_tempo2.sif psrplot -N 4x1 -p G -l pol=0-3 -j T -j "F 512" -g 1000x500 -D 2019-05-02-10\:08\:00_with_correction_applied_to_PP.png/png  2019-05-02-10\:08\:00.ar

This produces the following:

Calibration solutions

1240827912

The (coarse channel) solutions directly from the RTS (phases only):

Using vcsbeam v2.18 (mwalib must be >= v0.11.0):
$ mwa_plot_calibration -m /PATH/TO/1240826896_metafits_ppds.fits -c /PATH/TO/1240827912.metafits -C . -N 24 -R NONE -U 0,0 -X > solution.txt
$ /PATH/TO/plot_calibration.py solution.txt

After applying the following three corrections:

Divide the phases by a reference antenna (LGB8)
Zero the cross terms (PQ and QP)
Apply the phase slope correction to the top left matrix element

Using vcsbeam v2.18 (mwalib must be >= v0.11.0):
$ mwa_plot_calibration -m /PATH/TO/1240826896_metafits_ppds.fits -c /PATH/TO/1240827912.metafits -C . -N 24 > solution.txt
$ /PATH/TO/plot_calibration.py solution.txt