Type III Radio Burst Automatic Recognition Algorithm
The automatic recognition of the Type III radio burst using Hough Transform.
Installation
Python:
pip install type3detectMatlab:
git clone https://github.com/peijin94/type3detect.git
cd src/matlabExample
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.ipynbExample: 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}
}
