Search Fast Radio Bursts in Radioastron-project archive data

Installing

$ git clone https://github.com/akutkin/frb.git

• Create & activate virtual environment for installing dependencies

$ cd frb
$ wget https://github.com/pypa/virtualenv/archive/master.zip
$ unzip master.zip
$ python2 virtualenv-master/virtualenv.py ./venv
$ source venv/bin/activate

• Install dependencies inside virtual environment

$ pip2 install scipy astropy scikit-learn scikit-image matplotlib h5py sqlalchemy

Finding injected pulses in one file

• Download sample data

$ cd examples
$ wget https://www.dropbox.com/s/ag7rz88kjnblqzv/data.tgz
$ tar -xvzf data.tgz

• Run script

$ python2 caching.py

• Deactivate virtual environment

$ deactivate

This script will inject pulses in raw data and search for them using three algorithms. Each one begins with non-coherent de-dispersion. First one shear t-DM plane on universal value and average frequencies to find peaks in time and then DM. Last two use pre-processing the resulting t-DM plane to reduce the noise and exclude some extended regions of atypicaly high amplitude. Blobs of high intensity are found. Next, 2D elliptical gaussians are fitted to regions of individuals blobs in originalt-DM plane. Second algorithm chooses candidates with auto-selected threshold gaussian amplitudes and some other parameters of gaussians that are specific to narrow dispersed pulses. Third algorithm uses artificially injected pulses to train Gradient Boosting Classifier[Currently didn't used]. It uses features of fitted gaussians as well as numerous blob properties to build desicion surface in features space.

Searching pulses using fitted elliptical gaussians in t-DM place is much faster then using Gradient Boosting Classifier. It is because later needs training sample to be constructed & analyzed. Also it finds best parameters of classifier using grid of their values. All these steps (training of classifier) must be done only once for small portion of data.

Currently, amplitudes of injected pulses in training phase are set by hand. It will be fixed soon by analyzing amplitudes of noise pulses in apriori pulse-free small chunk of data.

Script will create png plots of found candidates in original dynamical spectra & t-DM plane in frb/examples directory and dump data on found candidates and data searched in frb/frb/frb.db SQLite database. It can be easily viewed/queried in Firefox with SQLite Manager addon.

Process experiment

• Login to frb computer with your credientials
• Clone frb repository, install virtual environment, activate it & install dependencies inside virtual environment (see Installing)
• Download experiment CFX-file

$ cd frb/frb
$ wget https://www.dropbox.com/s/8pcmgmed36fo8uy/RADIOASTRON_RAKS12EC_C_20151030T210000_ASC_V1.cfx

• Compile my5spec program for converting raw Mk5 data to txt-format

$ cd ../my5spec; /usr/bin/make

• Run example

$ cd ../frb
$ python2 pipeline.py

Script processes experiment (raks12ec, C-band, Noto & Yebes radiotelescopes). Results on data searched & pulse candidates are dumped to frb/frb/frb.db SQLite database. Finally, script check DB to find close (in time & DM) pulse candidates among searched antennas.

Using docker

There's no need to install any packages except docker itself

• Install docker package on your machine
• Run container with image and mount it to some directory host_dir on your host machine. It will take some time to download image with preinstalled OS & software.

$ docker run -it -v host_dir:/home/frb-dev/data ipashchenko/frb /bin/bash

• Inside container load data and start script

# cd frb-dev/examples
# wget https://www.dropbox.com/s/ag7rz88kjnblqzv/data.tgz
# tar -xvzf data.tgz
# python2 caching.py

• After it's execution copy results (images & DB file) to mounted dirrectory

# cp *.png ../data/.
# cp ../frb/frb.db ../data/.

• Results can be viewed in directory host_dir on your host machine.

TODOs

• Currently, my5spec fails to read raw data with some format (see issue #7) and fails to read ends of files (see issue #13).