As the frequency of electromagnetic waves becomes lower, the signal can penetrate deeper into the sea, while the installation and operation costs get higher. That is why only some of the developed countries operate Very-Low-Frequency (VLF) transmitters that can be used for sending electromagnetic signals to submersible vehicles. This talk will give a brief introduction to the effects of VLF transmitter signals on ionospheric cold plasma and energetic particles coming from the magnetosphere. We also review the signatures captured by Korean satellites, such as NextSat-1. Finally, we discuss the possible contribution of the recently launched SNIPE fleet to this topic.