Type III Radio Burst Automatic Recognition Algorithm

The automatic recognition of the Type III radio burst using Hough Transform.

Installation

Python

install from pypi

pip install type3detect

install from git

git clone https://github.com/peijin94/type3detect.git
cd src/python
python pip install .

Matlab:

git clone https://github.com/peijin94/type3detect.git
cd src/matlab

Example

Read fits file and detect type III radio bursts in dynamic spectrum.

import matplotlib.dates as mdates
import matplotlib.pyplot as plt
import numpy as np

from type3detect import detectRadioburst as drb
from type3detect import radioTools as rt

fname  = './LOFAR_20220701_070000_LBA_OUTER_S0.fits'

# preprocess
(dyspec,t_fits,f_fits,hdu) = drb.read_fits(fname) # read LOFAR dynspec fits
(dyspec,f_fits) = drb.cut_low(dyspec,f_fits,f_low_cut_val=30) # remove below freq (RFI)
(data_fits_new,data_fits_new_smooth) = drb.preproc(dyspec,gauss_sigma=1.5)

# binarization
bmap = drb.binarization(data_fits_new,N_order=6,peak_r=1.002)

# detect verticle features
lines = drb.hough_detect(bmap,dyspec,threshold=40,line_gap=10,line_length=30,
            theta=np.linspace(np.pi/2-np.pi/8,np.pi/2-1/180*np.pi,300))
line_sets = drb.line_grouping(lines)

# get electron beam information from radio bursts
(v_beam, f_range_burst, t_range_burst, model_curve_set,
     t_set_arr_set,f_set_arr_set,t_model_arr,f_model_arr
    )= drb.get_info_from_linegroup(line_sets,t_fits,f_fits)

# detailed demo in ./type3detect_demo.ipynb

Example: Implementation with for LOFAR dynamic spectrum.

Demo Notebook: type3detect_demo.ipynb

Binarization

Use several ways to transform the flux intensity data into binary. (LocalMax(matlab)) (binarization(Python))

Active-Contour method for Backbone

The Active Contour Method for the backbone of the radio burst (ACBone)

Take the result of the Hough transform as a initail position and iteratively move the line to find the backbone position. The demo code : (ACBone-Matlab, ACBone-Python)

Eventually, we can obtain the centerline of a Type III radio burst.

Citation

Make sure to cite the paper if you use the idea or code in this repo: A type III radio burst automatic analysis system and statistic results for a half solar cycle with Nançay Decameter Array data Peijin Zhang. A&A 2018.10

bibtex:

@article{zhang2018type,
  title={A type III radio burst automatic analysis system and statistic results for a half solar cycle with Nan{\c{c}}ay Decameter Array data},
  author={Zhang, PJ and Wang, Chuan Bing and Ye, Lin},
  journal={Astronomy \& Astrophysics},
  volume={618},
  pages={A165},
  year={2018},
  publisher={EDP Sciences}
}