伪随机信号编码技术在矿井电法中的应用前景

Application Prospect of Pseudorandom Signal Coding Technology in Mine Electric Prospecting

煤矿井下电磁干扰严重制约了电法探测精度的提高。伪随机信号是具有一定随机性、周期性、可以预先确定和重复产生的二进制混频编码信号,在通讯、地面电法勘探等领域应用广泛。2n序列伪随机信号是根据三元素自封闭加法原理,对不同频率的方波信号进行混频编码后,通过重复复制生成的一种周期信号。该信号具有多频点对数分布、主频幅值相当、抗干扰能力强等优势。如果将其作为煤矿井下电法的激励场源,有望实现信号的多频同时等幅发射,提高采集效率,改善探测结果;但受煤安条件限制,2n序列伪随机信号频点数要受到一定的限制。

Coalmine underground EMI will seriously restrict electric prospecting accuracy improvement. The pseudorandom signal is a kind of binary mixing coding signal with certain randomness and periodicity, can be determined in advance and repeatedly generated, widely used in communications, surface electric prospecting and other domains. The 2^n sequence pseudorandom signal is a kind of periodic signal based on three elements self closing addition principle, after mixing coding for square wave signals of different frequencies, through repeated replication generated. The signal has superiorities of multi-frequency point logarithmic distribution, equivalent dominant frequency amplitudes, and excellent interference resistance etc. If used it as coalmine underground electric prospecting exciting- field source, can be expected to achieve signal multi-frequency simultaneous constant amplitude emission, increase acquisition efficiency, and improve prospecting results; but subject to coalmine security condition, 2^n sequence pseudorandom signal number of frequency points shall be restricted in a certain extent.