基于Hilbert-Huang变换的瞬时频率法用于水下沉积物分类

Marine sediment classification using the instantaneous frequency technique based on Hilbert Huang Transform

针对使用频率范围为2—7kHz的chirp浅层剖面仪系统,本文基于弛豫时间模型,采用瞬时频率的方法实现水下沉积物的分类。所采用的弛豫时间模型综合了声波在海底沉积物中的各种散射能量损失因素,并归结为一个参数。采用脉冲功率谱的中心频率偏移量来估算衰减,提出用Hilbert—Huang变换(HHT)计算瞬时频率,并对试验数据进行了分析。

Based on relaxation time attenuation model, the instantaneous frequency technique is adopted for the chirp profiler operating in the frequency range of 2kHz -7kHz to realize the classification of the marine seafloor ssediments. The relaxation time model combines the various dissipative energy loss mechanism of sound in marine sediments into a single parameter. Using the frequency shift in the pulse spectrum,the attenuation is estimated. Hilbert Huang transform （HHT） is used to estimate of the instantaneous frequency. Some field data are examined using this new technique.