Amplitude Statistics of Sea Clutter by Three-parameter Log-Weibull Distribution

Abstract

We have observed sea clutter using an S-band radar with a frequency of 3.05GHz, a beamwidth of 1.8°, a pulsewidth of 0.5µs, and a pulse-repetition frequency of 1,600Hz. To estimate sea clutter amplitude statistics, We introduce new three-parameter log-Weibull distribution and the Minimum Description Length (MDL) principle. We have found that the sea clutter amplitude obey the three-parameter log-Weibull distribution with the shape parameter of c=24.42 for entire data and the log-normal, Weibull, log-Weibull, and three-parameter log-Weibull distributions with the shape parameters of σ=0.183 to 0.215, c=6.17 to 7.81, c=30.16 to 32.58, and c=21.20 to 87.31, respectively, for data within the beam width of an antenna. The number of best fit of the log-normal, Weibull, log-Weibull, and three-parameter log-Weibull distributions to data are 2, 4, 2, and 4, respectively, from 12 range sweep numbers. It is found that location parameter of the three-parameter log-Weibull distribution works effectively.