High-performance passive millimeter-wave imaging

Appleby, Roger; Gleed, David G.; Anderton, Rupert N.; Lettington, Alan H.

doi:10.1117/12.135857

Cited by 22 publications

(6 citation statements)

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“…However, the higher frequency of millimeter waves leads to higher atmosphere attenuation, precipitation attenuation, diffraction effects, and scattered effects, which means millimeter waves are largely absorbed by gases or humidity in the environment and are bad at penetrating solid material and traveling long distance [32]. Nevertheless, compared to optical waves that have higher frequencies, atmosphere attenuation of millimeter waves is much less, and more importantly, the propagation of millimeter waves is less influenced by the lights and thermal effects from the environment [33].…”

Section: Characteristicsmentioning

confidence: 99%

Morphophysiological and Proteomic Responses on Plants of Irradiation with Electromagnetic Waves

Zhong

Wang

et al. 2021

IJMS

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Electromagnetic energy is the backbone of wireless communication systems, and its progressive use has resulted in impacts on a wide range of biological systems. The consequences of electromagnetic energy absorption on plants are insufficiently addressed. In the agricultural area, electromagnetic-wave irradiation has been used to develop crop varieties, manage insect pests, monitor fertilizer efficiency, and preserve agricultural produce. According to different frequencies and wavelengths, electromagnetic waves are typically divided into eight spectral bands, including audio waves, radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. In this review, among these electromagnetic waves, effects of millimeter waves, ultraviolet, and gamma rays on plants are outlined, and their response mechanisms in plants through proteomic approaches are summarized. Furthermore, remarkable advancements of irradiating plants with electromagnetic waves, especially ultraviolet, are addressed, which shed light on future research in the electromagnetic field.

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Section: Characteristicsmentioning

confidence: 99%

Morphophysiological and Proteomic Responses on Plants of Irradiation with Electromagnetic Waves

Zhong

Wang

et al. 2021

IJMS

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“…Thus, the plane wave at time t from an angle 9 from the aperture plane is r(p, t) exp{j((ct + px))}, where p = cos 8, x is the distance parallel to the aperture plane, and r(p, t) is the complex amplitude associated with a particular angle of arrival. Finally, we assume that E[r(pi,t)r*(p2,t)] = I(p')6(p' P2) (1) Consider an aperture centered at x = 0. If we assume that the elements of the aperture are insensitive to direction or that the scene exists only for a small angle from perpendicular to the aperture, then the waveform impinging upon the aperture element at a displacement x is a superposition of the waveforms from all angles and is given by…”

Section: Clarifying the Superresolution Problem 21 Imaging Equationmentioning

confidence: 99%

<title>Analysis of the difficulties and possibilities for superresolution</title>

Reeves

1997

Passive Millimeter-Wave Imaging Technology

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In passive imaging, the spatial information acquired is strictly bandlimited. Because of this limitation, a number of postprocessing strategies have been proposed to accomplish a measure of superresolution. These strategies incorporate prior information about the image to improve resolution. We show that unless this information is shift-variant, it is unable to contribute to any superresolution. Shift-variant information about the image can be shown to be equivalent to forcing a correlation among the basis images that represent the image. We show that accomplishing superresolution from this correlation is very difficult and has fundamental limitations. Finally, we discuss the potential gains available from using prior information and propose an acquisition strategy that in some cases could improve the potential for superresolution.

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“…But in comparing with traditional undestanding oflocal oscillator as monochromatc generator in case of JJ we have deal with reality of noise heterodyne. Central frequency of JJ generation are controlled by famous relation 2eV hco [5] (1) where k is Boltzmannn's constant, and e and h are the electron charge and Planck's constant, is physical temperature of JJ, R is the JJ resistance, respectively. So JJ itseif emits a spectrum within effective bandwidth A F (About 160 MHz ofband on one Ohm ofresistanse ofJJ ).…”

Section: The Receiving "Pixel" At the Base Of Josephson Junctionmentioning

confidence: 99%

“…the creation of multibeam system with radiometer sensors array. So, the observation time lengthens significantly [1] in panoramic scanning devices, which restricts information processing rate. Futhermore, the need for scanning devices, which are usially mechanical, makes such devices not only too bulky, but some times it is not possible to realise their principal possibilities on sensitivity according to many problems on matching with antenna, especially in mixer conversion systems.…”

Section: Introductionmentioning

confidence: 99%

<title>Possibilities of designing of matrix millimeter imaging systems at the base of superconducting elements</title>

Denisov

1997

Passive Millimeter-Wave Imaging Technology

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Integration ofplurality ofradiometers into a panoramic receiving systems seems efficient for realisation of "radiovision"(imaging) systems without scanning if small-sized sensors with good operating parameters are available. The use of Josephson Junctions (JJ) in self-pumping mode as one ofvarious heterodyne detection methods is of principally new particular interest and trend, when we consider the properties such as the sensitivity, possibilities of frequency electroning tuning in big band, integrations with HEMT's and other nontraditional technical decisions, including the measuring of frequency of active signals on JJ. According to experimental and theoretical results it is possible to get the sensitivity not less than 0,0 1K in 3 mm wave band at cooling temperature 20-30 K in passive imaging system at the base ofmatrix ofJJ +HEMT's "pixels".

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High-performance passive millimeter-wave imaging

Cited by 22 publications

References 0 publications

Morphophysiological and Proteomic Responses on Plants of Irradiation with Electromagnetic Waves

Morphophysiological and Proteomic Responses on Plants of Irradiation with Electromagnetic Waves

<title>Analysis of the difficulties and possibilities for superresolution</title>

<title>Possibilities of designing of matrix millimeter imaging systems at the base of superconducting elements</title>

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