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  2. Fresnel equations - Wikipedia

    en.wikipedia.org/wiki/Fresnel_equations

    But, for given amplitude (as noted above), the component of the Poynting vector in the y direction is proportional to the geometric factor cos θ and inversely proportional to the wave impedance Z. Applying these corrections to each wave, we obtain two ratios multiplying the square of the amplitude transmission coefficient:

  3. Signal-to-noise ratio - Wikipedia

    en.wikipedia.org/wiki/Signal-to-noise_ratio

    In the above formula, P is measured in units of power, such as watts (W) or milliwatts (mW), and the signal-to-noise ratio is a pure number. However, when the signal and noise are measured in volts (V) or amperes (A), which are measures of amplitude, [note 1] they must first be squared to obtain a quantity proportional to power, as shown below:

  4. Root mean square - Wikipedia

    en.wikipedia.org/wiki/Root_mean_square

    and the RMS for a function over all time is = [()]. The RMS over all time of a periodic function is equal to the RMS of one period of the function. The RMS value of a continuous function or signal can be approximated by taking the RMS of a sample consisting of equally spaced observations.

  5. Periodogram - Wikipedia

    en.wikipedia.org/wiki/Periodogram

    A power spectrum (magnitude-squared) of two sinusoidal basis functions, calculated by the periodogram method. Two power spectra (magnitude-squared) (rectangular and Hamming window functions plus background noise), calculated by the periodogram method.

  6. Reflection coefficient - Wikipedia

    en.wikipedia.org/wiki/Reflection_coefficient

    In telecommunications and transmission line theory, the reflection coefficient is the ratio of the complex amplitude of the reflected wave to that of the incident wave. The voltage and current at any point along a transmission line can always be resolved into forward and reflected traveling waves given a specified reference impedance Z 0.

  7. Free-space path loss - Wikipedia

    en.wikipedia.org/wiki/Free-space_path_loss

    In telecommunications, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). [1]

  8. Zoeppritz equations - Wikipedia

    en.wikipedia.org/wiki/Zoeppritz_equations

    The Zoeppritz equations consist of four equations with four unknowns [] = [⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡ ⁡] [⁡ ⁡ ⁡ ⁡]R P, R S, T P, and T S, are the reflected P, reflected S, transmitted P, and transmitted S-wave amplitude coefficients, respectively, =angle of incidence, =angle of the transmitted P-wave, =angle of reflected S-wave and =angle of the ...

  9. Full width at half maximum - Wikipedia

    en.wikipedia.org/wiki/Full_width_at_half_maximum

    Half width at half maximum (HWHM) is half of the FWHM if the function is symmetric. The term full duration at half maximum (FDHM) is preferred when the independent variable is time . FWHM is applied to such phenomena as the duration of pulse waveforms and the spectral width of sources used for optical communications and the resolution of ...