数字滤波技术在潮汐观测中的应用研究

潮汐是重要的海洋物理要素。瞬时变化的海面高度信息除了包含潮汐信息外,还包括波浪等高频干扰信息,因此需要对干扰信息进行滤除。如何从获取到的海面瞬时高度变化中提取出潮汐信息就成为一个关键问题。海洋学中通常是通过低通滤波来获取低频的潮汐信息。通过分析常用的3种低通数字滤波的方法,即滑动平均法、快速傅里叶变换法和小波变换法,对3种低通滤波方法应用于潮汐数据处理的效果进行了比较分析,得出滑动平均法在潮汐信息提取中具有较高应用价值的结论。

Study on the Application of Digital Filtering Technique in Tide Observation

Tide is an important marine physical element. The instantaneous change of the sea surface height contains not only the tide information, but also the wave interferences in high frequency, so it is necessary to filter out the interferences. How to extract the tide information from the instantaneous change of the sea surface height has become a key problem. In oceanographic practice, the tide information in low frequency is usually obtained through a low-pass filter. This paper analyzes the three commonly used digital low-pass filtering methods: the sliding average method, fast Fourier transform and wavelet transform; compares the effects of the three methods in tidal data processing; and concludes that the sliding average method has high application value in tide information extraction.