ワイブル分布の部分的Q-Q確率プロットにより分析したシークラッタとウェザークラッタの統計的性質

抄録

In stormy weather due to typhoon hitting the Kanto district, I have observed sea and weather clutter including a target (ship) 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 analyze the sea and weather clutter amplitude statistics, I have proposed new partial Q-Q plot, which is more rigorous fit of the distribution to the data than conventional Q-Q plot. The partial Q-Q plot is as follows : locate the maximum value on the histogram of observed data and find the point on Q-Q plot corresponding to the maximum value. Fit the approximate line to this point and the nearest ones on both sides by least squares method. Adding a point nearest these ones, fit it similarly. Repeat them and select the approximate line giving the smallest RMSE (Root Mean Square Error). I have found that the sea and weather clutter amplitudes obey the Weibull distribution with the shape parameters of c = 2.88 for entire data and c = 2.68 to 4.08 for data within the beam width of an antenna.