Spectrum AtlasAn interactive atlas of the radio-frequency environment
The world is constantly emitting electromagnetic signals. Move across eleven orders of magnitude to see what produces them, how they propagate, and how wavelength changes across the radio spectrum.
Interactive spectrum atlas
Select a band or move the control. The scale is logarithmic—each step represents a tenfold increase in frequency.
Lightning can be heard beyond the horizon
At 10 kHz, one wavelength is 30 km—across a region or country.
Lightning sferics, tweeks, whistlers and D-region ionosphere effects.
VLF transmitters, specialised communications and timing or navigation signals.
Two overlapping worlds
Natural phenomena and engineered systems can occupy the same frequency regions. Their origins and propagation distinguish them.
Lightning launches energy across an enormous frequency range. Its low-frequency components can propagate around the planet, carrying information about the storm and the path they crossed.
Airports, ports, grids and cities create a dense electromagnetic landscape, from power-frequency fields to radio, navigation, radar and satellite transmissions.
A wavelength intuition
Frequency and wavelength are inversely related. That is why the same atlas moves from planetary-scale propagation to systems that fit inside a vehicle, a room or a handheld device.
Keep exploring
Move through the atlas again and compare how the sources, propagation and wavelength change from sub-hertz fields to gigahertz radio.
