When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Line-of-sight propagation - Wikipedia

    en.wikipedia.org/wiki/Line-of-sight_propagation

    The rays or waves may be diffracted, refracted, reflected, or absorbed by the atmosphere and obstructions with material and generally cannot travel over the horizon or behind obstacles. In contrast to line-of-sight propagation, at low frequency (below approximately 3 MHz ) due to diffraction , radio waves can travel as ground waves , which ...

  3. Cosmic noise - Wikipedia

    en.wikipedia.org/wiki/Cosmic_noise

    Cosmic noise, also known as galactic radio noise, is a physical phenomenon derived from outside of the Earth's atmosphere. It is not actually sound, and it can be detected through a radio receiver , which is an electronic device that receives radio waves and converts the information given by them to an audible form.

  4. Extremely low frequency - Wikipedia

    en.wikipedia.org/wiki/Extremely_low_frequency

    The rise of the noise at low frequencies (left side) is radio noise caused by slow processes in the Earth's magnetosphere. Due to their extremely long wavelength, ELF waves can diffract around large obstacles, are not blocked by mountain ranges or the horizon, and can travel around the curvature of the Earth.

  5. NASA explains the mysterious pulsing noise in space coming ...

    www.aol.com/nasa-explains-mysterious-pulsing...

    "The space station audio system is complex, allowing multiple spacecraft and modules to be interconnected, and it is common to experience noise and feedback," NASA said on X. NASA added that the ...

  6. NASA offers explanation for bizarre 'trumpet noise' phenomena

    www.aol.com/news/2015-05-22-nasa-attempts-to...

    Eerie noises have been recorded all over the world recently. NASA is now offering up a possible explanation.

  7. Skywave - Wikipedia

    en.wikipedia.org/wiki/Skywave

    Radio waves (black) reflecting off the ionosphere (red) during skywave propagation. Line altitude in this image is significantly exaggerated and not to scale. In radio communication, skywave or skip refers to the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere.

  8. Atmospheric noise - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_noise

    The sum of all these lightning flashes results in atmospheric noise. It can be easily heard with any AM radio or SSB receiver tuned to an unused frequency. [4] The heard static is a combination of white noise (cumulative of distant thunderstorms) and impulse noise (from relatively nearby thunderstorms, if any). The power-sum varies with seasons ...

  9. Gravitational wave - Wikipedia

    en.wikipedia.org/wiki/Gravitational_wave

    This leads to noise at the output of the detector, much like radio static. In addition, for sufficiently high laser power, the random momentum transferred to the test masses by the laser photons shakes the mirrors, masking signals of low frequencies. Thermal noise (e.g., Brownian motion) is another limit to sensitivity