Chirplets are wavelets that are transmitted by a chirp sub-bottom profiler (SBP) system. They contain multiple frequencies, typically in the kHz range, and are modulated linearly within a fixed signal length, which makes efficient data analysis possible. However, when chirp SBP field data are recorded, they are usually not raw but have gone through a matching filter and been converted to a Klauder wavelet section or signal envelope. When pre-processed data are reviewed, anomalies can easily be distinguished by sight, and since the data are not raw, reliable quantitative analysis of physical properties is unlikely. Moreover, as chirplets are transmitted through media, their waveforms often become distorted, creating many difficulties in performing analysis of physical properties following data processing. In this study, raw data were used as input to perform an accurate physical analysis of the background media and anomalies at the site of a 600-year-old shipwreck off the coast of Korea. During data processing, an optimal chirplet found through an analysis of the seabed reflection in the raw data was used, instead of the original chirplet set that was applied during acquisition. Conventional data processing was performed in addition to sparse-spike deconvolution and acoustic impedance conversion, using the optimal chirplet found in the raw data. The acoustic impedance results obtained by using the optimal chirplet had a higher level of accuracy when determining the properties of the medium and identifying anomalies, compared to those obtained when the original chirplet was used.

中文翻译：

---

使用chi SBP原始数据中分析的最佳chi的声阻抗转换研究

线性调频小波是通过线性调频次底轮廓仪（SBP）系统传输的小波。它们包含多个频率（通常在kHz范围内），并在固定信号长度内进行线性调制，从而可以进行有效的数据分析。但是，当记录线性调频脉冲SBP场数据时，它们通常不是原始数据，而是经过匹配的滤波器并转换为Klauder小波部分或信号包络。当检查预处理数据时，可以很容易地通过视觉识别异常，并且由于数据不是原始数据，因此不太可能对物理性质进行可靠的定量分析。此外，由于线性调频脉冲通过介质传输，它们的波形通常会失真，从而在数据处理之后进行物理特性分析时造成许多困难。在这个研究中，原始数据被用作输入数据，对韩国沿海600年沉船事件的背景介质和异常情况进行准确的物理分析。在数据处理期间，使用了通过对原始数据中的海床反射进行分析而找到的最佳rp，而不是在采集过程中应用的原始chi。除了使用稀疏峰值去卷积和声阻抗转换外，还使用原始数据中发现的最佳线性调频脉冲进行常规数据处理。与使用原始chi声波时相比，使用最佳chi声波获得的声阻抗结果在确定介质的性质和识别异常时具有更高的准确性。