Out in the no-mans land of the international waters are the only means of communication with the submarines to use radio in the vlf or elf range.
在茫茫大洋深处，唯一可用的通信手段就是甚低频或者极低频无线电。
2
The signal will have attenuation and disturbance due to environmental factors in the process of VLF radio wave propagation, which will impact the reliability of submarine communication.
甚低频(VLF)电波传播过程中因环境因素影响会使信号产生衰减与扰动，导致潜艇收信可靠性下降。
3
Abstract: the VLF Through-the-Earth Communication system is recognized as the most reliable way of conveying dispatching information due to its special transmission media.