Hands-On Edge Analytics with Azure IoT

VLF and LF

VLF sits in the 3 kHz to 30 kHz range in the RF spectrum with wavelengths from 100 km to 10 km respectively. Due to the relatively large wavelengths of VLF signals, the reflection of the signal is limited. This makes the VLF band useful for marine applications such as submarines. The following diagram illustrates this concept:

As you can see in the preceding diagram, lower frequencies penetrate surfaces better than higher frequencies. Think of the night club playing loud music. It is the lower frequencies that you hear the most when standing outside the club.

Sitting in the 30 kHz to 300 kHz range with wavelengths between 10 km ...