两步SVD在极低频电场透地通信中的应用

Application of Two-step SVD Filter in through-the-earth ELF Communications

摘要:

在极低频电场透地通信中，通常同步采集 2 个互相垂直的电场水平分量。当收发距较大时，采集获得的电场数据往往具有较小的信噪比，接收信号严重受到噪声的干扰，所传递的信息不清晰甚至错误。因此，当在极低频电场透地通信数据信噪比较低时，需要对其进行滤波处理，压制噪声成分，提高数据的质量。提出了一种两步奇异值分解滤波方法，该方法第 1 步压制极低频电场透地通信数据中较强的噪声，第 2 步在第 1 步的基础上继续压制数据中残留的噪声。将该方法应用到某湖上极低频电场透地通信数据中，处理结果表明，该方法可以有效改善各接收点电场数据的质量，极大地提高了数据的信噪比。

Abstract:

In through-the-earth ELF communications，two mutually perpendicular components of the electric field are usually collected and recorded. When the receiver is far from the transmitter，the signal-to-noise ratio of the collected ELF data is low，the received signal is seriously interfered by noise，and the transmitted information is not clear or even wrong. Therefore，when the signal-to-noise ratio in through-the-earth ELF communications is low，it is necessary to filter the data to suppress the noise components，and improve the quality of the data. In this paper，a two-step singular value decomposition（SVD）filter is proposed. The main noise is reduced in the first step，and the residual noise is reduced in the second step. The processing results of measured ELF data indicate that the proposed method can effectively reduce noise and improve the signal-to-noise ratio of the ELF data.