VLF
Below AM frequencies
VLF stands for very low frequency, the band of radio waves from 3 to 30 kilohertz.
These long wavelengths can penetrate seawater and the earth's surface, making VLF useful for submarine communication and underground navigation.
VLF signals also reach into mines and caves where higher frequencies cannot.
Electrical signal interference
- whistlersThose producing lip-blown tones
- tweeksSmall refinements made
- auroraAtmospheric light display
- magnetosphereCelestial body's protective field
ionosphere · plasma · lightning · geomagnetic · space weather · solar wind · radiation belt · electromagnetic
Below the surface
- navyMaritime military force
- transmitterSignal-emitting device
- antennaBroadcast signal receiver
- sonarUnderwater detection by echoes
communication · depth · nuclear submarine · fleet · maritime · warfare · stealth · propagation
Broadcast signal receiver
- transmitterSignal-emitting device
- receiverOne who accepts transmission
- towerTall slender edifice
- mastVessel's sail support
coil · ferrite · induction · impedance · resonance · tuning · electronics · engineering
Act of spreading widely
- skywaveRadio reflected by atmosphere
- ionosphericOf the charged atmosphere
- electromagneticInvolving electric and magnetic fields
- wavelengthSpatial repetition interval
kilohertz · spectrum · bandwidth · modulation · low-frequency · long-distance · penetration · attenuation
Guiding light source
- navigationalRelated to finding direction
- LORANRadio-based navigation system
- aeronauticalOf aircraft science
- maritimeOf the sea
positioning · timing · waypoint · synchronization · coordinate
atmospherics
Electrical signal interference
magnetosphere · ionosphere · plasma · lightning · geomagnetic · space weather · solar wind · radiation belt · electromagnetic · chorus
underwater
Below the surface
- navyMaritime military force
- transmitterSignal-emitting device
- antennaBroadcast signal receiver
sonar · communication · depth · nuclear submarine · fleet · maritime · warfare · stealth · propagation · signal
antenna
Broadcast signal receiver
- transmitterSignal-emitting device
- receiverOne who accepts transmission
- towerTall slender edifice
mast · coil · ferrite · induction · impedance · resonance · tuning · electronics · engineering · signal processing
propagation
Act of spreading widely
- skywaveRadio reflected by atmosphere
- ionosphericOf the charged atmosphere
- electromagneticInvolving electric and magnetic fields
wavelength · kilohertz · spectrum · bandwidth · modulation · low-frequency · long-distance · penetration · attenuation · reflection
beacon
Guiding light source
- navigationalRelated to finding direction
- LORANRadio-based navigation system
- aeronauticalOf aircraft science
maritime · positioning · timing · waypoint · synchronization · coordinate