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  2. Wave vector - Wikipedia

    en.wikipedia.org/wiki/Wave_vector

    In physics, a wave vector (or wavevector) is a vector used in describing a wave, with a typical unit being cycle per metre. It has a magnitude and direction. Its magnitude is the wavenumber of the wave (inversely proportional to the wavelength), and its direction is perpendicular to the wavefront. In isotropic media, this is also the direction ...

  3. Radar signal characteristics - Wikipedia

    en.wikipedia.org/wiki/Radar_signal_characteristics

    The pulse width ( ) (or pulse duration) of the transmitted signal is the time, typically in microseconds, each pulse lasts. If the pulse is not a perfect square wave, the time is typically measured between the 50% power levels of the rising and falling edges of the pulse. The pulse width must be long enough to ensure that the radar emits ...

  4. Wavelength - Wikipedia

    en.wikipedia.org/wiki/Wavelength

    The wavelength (or alternatively wavenumber or wave vector) is a characterization of the wave in space, that is functionally related to its frequency, as constrained by the physics of the system. Sinusoids are the simplest traveling wave solutions, and more complex solutions can be built up by superposition.

  5. Specular reflection - Wikipedia

    en.wikipedia.org/wiki/Specular_reflection

    Specular reflection, or regular reflection, is the mirror -like reflection of waves, such as light, from a surface. [1] The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal in the plane formed by ...

  6. Dispersion relation - Wikipedia

    en.wikipedia.org/wiki/Dispersion_relation

    In the physical sciences and electrical engineering, dispersion relations describe the effect of dispersion on the properties of waves in a medium. A dispersion relation relates the wavelength or wavenumber of a wave to its frequency. Given the dispersion relation, one can calculate the frequency-dependent phase velocity and group velocity of ...

  7. Refractive index - Wikipedia

    en.wikipedia.org/wiki/Refractive_index

    The refractive index, , can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is v = c/n, and similarly the wavelength in that medium is λ = λ 0 /n, where λ 0 is the wavelength of that light in vacuum.

  8. Optical resolution - Wikipedia

    en.wikipedia.org/wiki/Optical_resolution

    The ability of a lens to resolve detail is usually determined by the quality of the lens, but is ultimately limited by diffraction.Light coming from a point source in the object diffracts through the lens aperture such that it forms a diffraction pattern in the image, which has a central spot and surrounding bright rings, separated by dark nulls; this pattern is known as an Airy pattern, and ...

  9. Speckle (interference) - Wikipedia

    en.wikipedia.org/wiki/Speckle_(interference)

    [clarification needed] We determine the size of this area by the diffraction-limited resolution of the lens which is given by the Airy disk whose diameter is 2.4λu/D, where λ is the wavelength of the light, u is the distance between the object and the lens, and D is the diameter of the lens aperture. (This is a simplified model of diffraction ...