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  2. Narrowband - Wikipedia

    en.wikipedia.org/wiki/Narrowband

    Narrowband signals are signals that occupy a narrow range of frequencies or that have a small fractional bandwidth. [1] In the audio spectrum, narrowband sounds are sounds that occupy a narrow range of frequencies. In telephony, narrowband is usually considered to cover frequencies 300–3400 Hz, i.e. the voiceband.

  3. Hyperspectral imaging - Wikipedia

    en.wikipedia.org/wiki/Hyperspectral_imaging

    Each image represents a narrow wavelength range of the electromagnetic spectrum, also known as a spectral band. These "images" are combined to form a three-dimensional ( x , y , λ ) hyperspectral data cube for processing and analysis, where x and y represent two spatial dimensions of the scene, and λ represents the spectral dimension ...

  4. Ultra Narrowband - Wikipedia

    en.wikipedia.org/wiki/Ultra_Narrowband

    An ultra narrowband receiver is highly selective [2] and can reject noise and interference which may enter the receiver outside its narrow bandwidth, enabling an acceptable signal-to-noise ratio to be achieved with a relatively weak received signal. Consequently, transmitter power levels can be low and the effective range of transmissions may ...

  5. Spread spectrum - Wikipedia

    en.wikipedia.org/wiki/Spread_spectrum

    Practical synchronous digital systems radiate electromagnetic energy on a number of narrow bands spread on the clock frequency and its harmonics, resulting in a frequency spectrum that, at certain frequencies, can exceed the regulatory limits for electromagnetic interference (e.g. those of the FCC in the United States, JEITA in Japan and the ...

  6. Fourier-transform infrared spectroscopy - Wikipedia

    en.wikipedia.org/wiki/Fourier-transform_infrared...

    The throughput advantage is important for high-resolution FTIR, as the monochromator in a dispersive instrument with the same resolution would have very narrow entrance and exit slits. In 1966 Janine Connes measured the temperature of the atmosphere of Venus by recording the vibration-rotation spectrum of Venusian CO 2 at 0.1 cm −1 resolution ...

  7. Multispectral imaging - Wikipedia

    en.wikipedia.org/wiki/Multispectral_imaging

    Dividing the spectrum into many bands, multispectral is the opposite of panchromatic, which records only the total intensity of radiation falling on each pixel. [14] Usually, Earth observation satellites have three or more radiometers. Each acquires one digital image (in remote sensing, called a 'scene') in a small spectral band.

  8. Spectrum (physical sciences) - Wikipedia

    en.wikipedia.org/wiki/Spectrum_(physical_sciences)

    In the physical sciences, the spectrum of a physical quantity (such as energy) may be called continuous if it is non-zero over the whole spectrum domain (such as frequency or wavelength) or discrete if it attains non-zero values only in a discrete set over the independent variable, with band gaps between pairs of spectral bands or spectral ...

  9. Nondispersive infrared sensor - Wikipedia

    en.wikipedia.org/wiki/Nondispersive_infrared_sensor

    A nondispersive infrared sensor (or NDIR sensor) is a simple spectroscopic sensor often used as a gas detector.It is non-dispersive in the fact that no dispersive element (e.g a prism or diffraction grating as is often present in other spectrometers) is used to separate out (like a monochromator) the broadband light into a narrow spectrum suitable for gas sensing.