CAJ | 학술논문

K分布模型在极化合成孔径雷达(PolSAR)图像建模领域中获得广泛应用。其模型参数估计的精度将直接影响到模型拟合的准确性。目前普遍采用的K分布参数估计方法是基于协方差矩阵Mellin变换的对数累积量的估计方法。但是该方法没有解析的表达式，数值计算运算时间较长，另外在形状参数a<1时估计偏差较大。为此该文提出一种基于|z |r lg|z |混合矩的参数估计新方法，该方法对不同形状参数a值下的参数估计具有较好的适应性，并且在a值较小时估计性能优于对数累积量方法。同时在r=1/d时该方法有解析的表达式，其运算时间优于对数累积量方法。最后用仿真数据和实测数据对新方法和已有参数估计方法的结果进行了比较，验证了基于混合矩估计方法的准确性与有效性。该方法为PolSAR图像统计模型参数的快速有效估计提供了新手段。
K분포모형재겁화합성공경뢰체(PolSAR)도상건모영역중획득엄범응용。기모형삼수고계적정도장직접영향도모형의합적준학성。목전보편채용적K분포삼수고계방법시기우협방차구진Mellin변환적대수루적량적고계방법。단시해방법몰유해석적표체식，수치계산운산시간교장，령외재형상삼수a<1시고계편차교대。위차해문제출일충기우|z |r lg|z |혼합구적삼수고계신방법，해방법대불동형상삼수a치하적삼수고계구유교호적괄응성，병차재a치교소시고계성능우우대수루적량방법。동시재r=1/d시해방법유해석적표체식，기운산시간우우대수루적량방법。최후용방진수거화실측수거대신방법화이유삼수고계방법적결과진행료비교，험증료기우혼합구고계방법적준학성여유효성。해방법위PolSAR도상통계모형삼수적쾌속유효고계제공료신수단。
The K-distribution is usually used to model the Polarimetric Synthetic Aperture Radar (PolSAR) imagery. The parameter estimation method for K-distribution is very important,which affects the fitting degree of the model. However, the classical method of matrix log-cumulants relies upon a nontrivial inversion of a nonlinear equation, which introduces a computationally expensive stage into the estimation procedure. Moreover, the bias is large when the sharp parametera is smaller than 1. Therefore, a new method for estimating the sharp parameter of K-distribution based on|z|rlg|z| is proposed. This method is more adaptable to parameter estimation under different sharp parameters, and the performance is better than matrix log-cumulantes whenais small. In addition, the proposed estimator has an analytical expression atr=1/d, which allows rapid caculation. Finally, the estimation accuracy of this new estimator is compared with previous ones through simulation data and real data. The results show that the new estimator is effective and robust, which is of practical value in solving the accurate parameter estimation of K-distribution.