Weak Signal Extraction from Lunar Penetrating Radar Channel 1 Data Based on Local Correlation
Weak Signal Extraction from Lunar Penetrating Radar Channel 1 Data Based on Local Correlation
复制标题
基于局部相关的探月雷达1通道数据微弱信号提取
DOI：
10.3390/electronics8050573
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发表时间：
2019-05-01
期刊：
影响因子：
2.9
通讯作者：
Zhang, Jianmin
中科院分区：
文献类型：
--
作者：
Jia, Zhuo;Liu, Sixin;Zhang, Jianmin
对月球表面结构的了解不仅可以提供有关月球地质的有用信息，而且还可以量化人类潜在的月球资源。玉兔号月球车上的双频月球穿透雷达（LPR）提供了一个特殊的机会，可以使用低频通道（通道1）了解数百米深度的地下结构，以及使用高频观测（通道2）了解风化层的层近地表地层结构。LPR的通道1数据具有非常低的信噪比。然而，从数据中提取弱信号是一个值得探索的问题。本文提出了一种基于局部相关性的弱信号提取方法，用于分析LPR CH-1数据，为月壤结构的研究提供便利。首先，我们建立了一个预处理工作流程，以提高信噪比（SNR）。其次，利用K-L变换分离出水平信号，再利用Seislet变换保留连续信号。然后，利用这两种去噪结果计算局部相关图，并构造一个时空相关的加权算子来抑制噪声残差。压制噪声后的微弱信号可为后续资料解释提供新的参考。最后，结合区域地质和前人的研究成果，对LPR CH-1数据进行了推测性解释。
Knowledge of the subsurface structure not only provides useful information on lunar geology, but it also can quantify the potential lunar resources for human beings. The dual-frequency lunar penetrating radar (LPR) aboard the Yutu rover offers a Special opportunity to understand the subsurface structure to a depth of several hundreds of meters using a low-frequency channel (channel 1), as well as layer near-surface stratigraphic structure of the regolith using high-frequency observations (channel 2). The channel 1 data of the LPR has a very low signal-to-noise ratio. However, the extraction of weak signals from the data represents a problem worth exploring. In this article, we propose a weak signal extraction method in view of local correlation to analyze the LPR CH-1 data, to facilitate a study of the lunar regolith structure. First, we build a pre-processing workflow to increase the signal-to-noise ratio (SNR). Second, we apply the K-L transform to separate the horizontal signal and then use the seislet transform (ST) to reserve the continuous signal. Then, the local correlation map is calculated using the two denoising results and a time–space dependent weighting operator is constructed to suppress the noise residuals. The weak signal after noise suppression may provide a new reference for subsequent data interpretation. Finally, in combination with the regional geology and previous research, we provide some speculative interpretations of the LPR CH-1 data.