The low frequency noise contaminant, which can be magnified due to the linear conversion from the acceleration spectrum to the displacement spectrum, is the major cause of the inaccuracy.

• 其中，由加速度谱转换为水位谱时受低频杂讯干扰，常使波谱形状产生严重扭曲，对于此一干扰，本文基于正规化波谱形状具有相似性之特性，建立一滤除杂讯能量之方法。