碟形浮标观测方向波谱误差分析及修正

改进了方向波谱的分析方法及噪声谱经验公式，使本法随测波环境及仪器特性自动修正经验参值，更易于实际应用。基于Maximum heave/pitch quad-spectrum method，由时域及频率域上的浮标动力反应数值计算，推求反应增益因子及相位延迟项，并进一步将其导入方向波谱计算，使其能修正资料浮标对波浪之轴不对称动态反应所造成的相位延迟不一致及主波向误差。经数值仿真验证，该方法的确能消减因资料浮标对波浪之轴不对称动态反应所造成的相位延迟及对主波向估算所造成之影响。应用花莲现场观测资料验证改良之主波向估算方法，得出是否考虑波浪运动与浮标运动间之振幅响应因子及相位延迟因子，所得之主波向的差异介于0－12℃之间。

Error analysis of the wave directional spectrum measurement by Disc Buoys

Data buoys, which have the characteristics of comparative reliability and robustness, are the most frequently applied devices for the measurement of oceanographical data. The objective of the present study is to improve the accuracy of directional spectra measurement and analyseis. In order to improve the accuracy of directional estimation, a proposed method is developed based on Maximum heave/pitch quad-spectrum method. The response gain factor and phase lag can be merged into the directional spectrum estimator to reduce errors. The new method is then validated by numerical simulations. The results demonstrate that the difference of the main direction between the target and the output ranges from 0 to 20 degrees when the method is applied to the field wave data.