Common Usage
Deployment without X11
Launch the ska-pst-dspsr docker image and mount the current working directory as /mnt/data
docker run -it -v $(pwd):/mnt/data -w /mnt/data \
artefact.skao.int/ska-pst-dspsr:0.0.4 bash
Deployment with X11
To run applications that require X11 (e.g. PGPLOT), it is necessary to provide the X11 connection details on the docker command line, as in the following examples.
Windows Subsystem for Linux (WSL2)
docker run --rm -it -v $(pwd):/mnt/data -w /mnt/data \
-v /tmp/.X11-unix:/tmp/.X11-unix -v /mnt/wslg:/mnt/wslg \
-e DISPLAY -e WAYLAND_DISPLAY -e XDG_RUNTIME_DIR -e PULSE_SERVER \
artefact.skao.int/ska-pst-dspsr:0.0.4 bash
Linux and FreeBSD
docker run --rm -it -v $(pwd):/mnt/data -w /mnt/data \
--net=host -e DISPLAY -v ${HOME}/.Xauthority:/home/pst/.Xauthority \
artefact.skao.int/ska-pst-dspsr:0.0.4 bash
Mac running XQuartz
Before running docker, it may be necessary to install and/or configure XQuartz.
Install XQuartz
Open XQuartz -> Preferences -> Security
Enable
Allow connections from network clients
If necessary, restart XQuartz
In an XQuartz terminal, run
xhost + localhost
With XQuartz installed and configured, run
docker run --rm -it -v $(pwd):/mnt/data -w /mnt/data \
-e DISPLAY=host.docker.internal:0 -v /tmp/.X11-unix:/tmp/.X11-unix \
artefact.skao.int/ska-pst-dspsr:0.0.4 bash
Examples
Simulated Square Wave
After launching the ska-pst-dspsr
docker container, download the following test data file; e.g.
curl -O https://astronomy.swin.edu.au/pulsar/data/pst_rectangular_pulse.tgz
This file contains simulated output of the PST Voltage Recorder containaing normally distributed noise that is amplitude-modulated by a square wave with a 20% duty cycle. This simulation was generated as described in the ska-pst-common example uses.
Unzip the tarball to unpack the three files that it contains
tar zxvf pst_rectangular_pulse.tgz
data_and_weights.ls
data/2023-08-05-11:07:09_0000000000000000_000000.dada
weights/2023-08-05-11:07:09_0000000000000000_000000.dada
To compute the average of the rectangular pulses
dspsr data_and_weights.ls
The output data file is named 2023-08-05-11:07:09.ar
and, if the docker container is launched with X11 configured,
the contents of this file can be plotted with
psrplot -p freq+ -jp -j "r .5" 2023-08-05-11:07:09.ar -D /xs
This will plot a phase-vs-frequency image of the pulsed intensity, with the power from both polarisations added together, like the following
It’s also possible to plot separate phase-vs-frequency images of the pulsed intensity for each polarisation; e.g.
psrplot -p freq+ -l pol=0,1 -j "r .5" 2023-08-05-11:07:09.ar -D /xs
Note that the pulsed intensity varies linearly with frequency independently in each polarisation.
Pulsar Observed at Parkes
After launching the ska-pst-dspsr
docker container, download the following test data file; e.g.
curl -O https://astronomy.swin.edu.au/pulsar/data/1644-4559.dada
This file contains an observation of PSR J1644-4559 made with the Parkes Radiotelescope using the CPSR2 backend. To see the header contents
dada_edit 1644-4559.dada
Among other things, this header information shows that the observation was made at a centre frequency of 1405 MHz using lower-sideband downconversion and a bandwidth of 64 MHz. To perform phase-coherent dispersion removal and compute the average pulse profile, use the convolving filterbank to simultaneously divide the band up into 128 frequency channels, and use four threads to speed things up.
dspsr -F 128:D 1644-4559.dada -t4
The output data file is named 2007-05-18-15:55:58.ar
and, if the docker container is launched with X11 configured,
the contents of this file can be plotted with
psrplot -pG -jp 2007-05-18-15:55:58.ar -D /xs
This will plot a phase-vs-frequency image of the pulsed intensity, with the power from both polarisations added together, like the following
Some of the things to notice in this plot include
the dispersive delay, which varies with radio frequency;
the narrow band of additional unpulsed flux near 1420.4 MHz, which is emitted by the neutral Hydrogen in our Galaxy along this line of sight; and
the wide band of additional on-pulse quantization noise, known as scattered power, which is particularly visible at the edges of the band.