以烘干法测定的含水率标定Topp公式4个参数的初始值,再通过“拟合参数-实验校正”过程对Topp公式的4个参数进行二次迭代修正。结果表明,①迭代过程是一个模型参数优化的过程,表现为模型的赤池信息量准则(AIC)随迭代次数的增加而减小,而模型拟合的相关系数随着迭代次数的增加逐渐趋近于1;②TDR的测量数据误差随着迭代次数的增加而减小,一次迭代后误差平均为8.10%,二次迭代后降为5.05%。

The iterative thinking was used to calibrate the parameters of time domain reflectometry(TDR),in which the initial four parameters of Topp equation were determined by the water content observed by drying method and then four parameters were amended through the“fitting parameters-experimental calibration” procedure based on iterative algorithm.The results showed that:①The iterative process was an parameter optimization process for Topp model,which was demonstrated by that Akaike Information Criterion(AIC)decreased with the increase of the number of iterations,and correlation coefficient of model fitting increased gradually to 1;②Error of TDR decreased sharply with the increase of iteration numbers,which was 8.10%and 5.05%after the first and the second iteration respectively.