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  2. Dynamic pressure - Wikipedia

    en.wikipedia.org/wiki/Dynamic_pressure

    In fluid dynamics, dynamic pressure (denoted by q or Q and sometimes called velocity pressure) is the quantity defined by: [1] = where (in SI units): q is the dynamic pressure in pascals (i.e., N/m 2, ρ (Greek letter rho) is the fluid mass density (e.g. in kg/m 3), and; u is the flow speed in m/s.

  3. Klystron - Wikipedia

    en.wikipedia.org/wiki/Klystron

    Electrically, this is similar to the two cavity oscillator klystron with considerable feedback between the two cavities. Electrons exiting the source cavity are velocity modulated by the electric field as they travel through the drift tube and emerge at the destination chamber in bunches, delivering power to the oscillation in the cavity.

  4. Waveguide (radio frequency) - Wikipedia

    en.wikipedia.org/wiki/Waveguide_(radio_frequency)

    In radio-frequency engineering and communications engineering, a waveguide is a hollow metal pipe used to carry radio waves. [1] This type of waveguide is used as a transmission line mostly at microwave frequencies, for such purposes as connecting microwave transmitters and receivers to their antennas, in equipment such as microwave ovens, radar sets, satellite communications, and microwave ...

  5. Radio transmitter design - Wikipedia

    en.wikipedia.org/wiki/Radio_transmitter_design

    A radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. Radio waves are electromagnetic waves with frequencies between about 30 Hz and 300 GHz. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the ...

  6. Doppler radio direction finding - Wikipedia

    en.wikipedia.org/wiki/Doppler_radio_direction...

    The magnitude of the shift is a function of the wavelength of the signal and the angular velocity of the antenna: S = ⁠ r W / λ ⁠ Where S is the Doppler shift in frequency (Hz), r is the radius of the circle, W is the angular velocity in radians per second, λ is the target wavelength and c is the speed of light in meters per second. [13]

  7. Radiosonde - Wikipedia

    en.wikipedia.org/wiki/Radiosonde

    A radiosonde is an automatic radio transmitter in the meteorological aids service usually carried on an aircraft, free balloon, kite or parachute, and which transmits meteorological data. Each radio transmitter shall be classified by the radiocommunication service in which it operates permanently or temporarily.

  8. Radio propagation - Wikipedia

    en.wikipedia.org/wiki/Radio_propagation

    Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. [1]: 26‑1 As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. [2]

  9. Sound velocity probe - Wikipedia

    en.wikipedia.org/wiki/Sound_Velocity_Probe

    This instrument can determine the salinity, temperature and pressure variables, and then calculate the sound velocity of the water using one of the many formulae available. [ 2 ] Secondly, the speed of sound may be directly measured using a small acoustic transducer and a reflecting surface, mounted at a known distance from the acoustic center ...