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CFAR processing by converting Weibull to Rayleigh distributions
Author(s) -
Sayama Shuji
Publication year - 2020
Publication title -
electronics and communications in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.131
H-Index - 13
eISSN - 1942-9541
pISSN - 1942-9533
DOI - 10.1002/ecj.12231
Subject(s) - weibull distribution , clutter , rayleigh distribution , beamwidth , constant false alarm rate , amplitude , shape parameter , akaike information criterion , statistics , pulse repetition frequency , mathematics , acoustics , radar , physics , computer science , probability density function , antenna (radio) , algorithm , optics , telecommunications
I have observed sea clutter containing a target (ship) using an X‐band radar with a frequency of 9.41 GHz, a beamwidth of 1.0°, a pulsewidth of 0.5 μs, and a pulse‐repetition frequency of 1600 Hz. To investigate the sea clutter amplitude statistics, I introduce the Akaike Information Criterion (AIC). I have found that the sea clutter amplitudes obey the Weibull distribution with the shape parameter of c = 2.83 for entire data and the log‐normal, Weibull, and log‐Weibull distributions with the shape parameters of σ = 0.439, c = 2.76 to 4.59, and c = 8.09 to 10.42, respectively, for data within the beam width of an antenna. The number of the smallest AIC (MAIC) of the log‐normal, Weibull, and log‐Weibull distributions to data are 1, 18, and 2, respectively, from 21 range sweep numbers. I have used a circuit to convert Weibull to Rayleigh distributions and a Cell‐Averaging (CA) LOG/CFAR circuit. It is found that ship is detected and sea clutter is suppressed with improvement of 31.43 dB by CFAR processing.