HY-2高度计海况偏差非参数估计模型研究

基于HY-2高度计数据,采用局部线性回归非参数估计方法,利用球谐核函数及局部可调带宽,对70和71周期的交叉点进行海况偏差非参数估计。依据解释方差、海况偏差与有效波高及风速的相关度和模型残差分析,检验评价模型。与相同数据集下的参数模型估计结果进行了分析比对,结果表明:所选定的非参数模型的海况偏差与有效波高和风速的相关度均处于较高水平,说明模型更为有效。在不同纬度段,非参数模型和参数模型各有所长,在北半球高纬度区域,非参数模型表现更优。

Study on Nonparametric Estimations Model of the Sea State Bias for the HY-2 Altimeter

The nonparametric model of estimated the sea state bias with the local linear regression estimation,the spherical Epanechnikov kernel function and the local adjustable bandwidth is established based on HY-2 altimeter data.The performances of this model are evaluated by the explained variances,the correlations between the sea state bias and the significant wave height or wind speed and residuals.Compared with the estimations of parametric model under the same dataset,the results show that the correlations between the sea state bias of the nonparametric model in this paper and the significant wave height or wind speed are higher which means the model is more effective.The nonparametric model and the parametric model both have their own merits in different latitudes.The nonparametric model performs better in high-latitudes of the northern hemisphere.