Distance measurement with the aid of electromagnetic waves

For radar applications, the W-band frequency range (75 – 110 GHz) is a good candidate for high-resolution distance measurement and remote detection of small or hidden objects in distances of 10 cm to ≫ 20 m. As electromagnetic waves in this frequency range can easily penetrate rough atmosphere like fog, smoke or dust, W-band radars are perfectly suited for automotive, aviation, industrial and security applications. Additional benefit is that atmosphere has an absorption minimum at 94 GHz, so relative small output power is sufficient to achieve long range coverage. By combining and enhancing knowledge from the disciplines of heterogeneous integration technology and compound semiconductor-technology, the Fraunhofer Institutes IAF, IPA and IZM developed a miniaturized and low cost 94 GHz radar module. Result of this approach is a highly miniaturized radar module built using a modular approach. The radar components are mounted on a dedicated RF-NF-hybrid PCB while the signal processing is done on a separate board stacked below. This hybrid RF-module is combined with highly integrated digital processing PCB via micro connectors in a way that the radar system and an adapted conical HDPE-lens fit into an aluminum housing of 42×80×27 mm3 with a weight of only 160 grams for the whole module. The paper will describe the technological basis for such a frequency modulated continuous wave [FMCW] W-band radar module and describe in detail the technological features that enabled the assembly of such a miniaturized but high-performance system. The module yields an evaluated distance measurement accuracy of 5 ppm (5 μm deviation per meter target distance) while its low weight and small dimensions pave the way for a variety of new applications, including mobile operation.

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Review of electromagnetic waves-based distance measurement technologies for remote monitoring of civil engineering structures

Measurement ◽

10.1016/j.measurement.2021.109193 ◽

2021 ◽

Vol 176 ◽

pp. 109193 ◽

Cited By ~ 1

Author(s):

Yiming Liu ◽

Yi Bao

Keyword(s):

Remote Monitoring ◽

Electromagnetic Waves ◽

Civil Engineering ◽

Distance Measurement ◽

Engineering Structures ◽

Civil Engineering Structures

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Comparative analysis of the accuracy requirements of the equipment for determining the mean integral refractive index of air using different realizations of the gradient method

Ukrainian Metrological Journal ◽

10.24027/2306-7039.2.2021.236075 ◽

2021 ◽

pp. 20-24

Author(s):

Pavel Neyezhmakov ◽

Alexander Prokopov ◽

Tatiana Panasenko ◽

Andrii Shloma

Keyword(s):

Refractive Index ◽

Gradient Method ◽

Electromagnetic Waves ◽

Meteorological Parameters ◽

Distance Measurement ◽

Integral Group ◽

Long Distance ◽

Uncertainty Of Measurements ◽

Group Refractive Index ◽

The Mean

The speed of propagation of electromagnetic waves in the Earth’s atmosphere differs from the speed of their propagation in a vacuum, which is one of the main factors that have a significant impact on the accuracy of long distance measurement. This influence is taken into account in long distance measurement with the correction for the mean integral group refractive index of air, which depends on such meteorological parameters as temperature, atmospheric pressure and relative air humidity. The purpose of this work is to compare the accuracy requirements for equipment designed to measure temperature, pressure, and relative humidity required to determine the above correction by the gradient method using the Euler-Maclaurin quadrature formula (hereafter, the Euler-Maclaurin method) and the formula based on Hermite interpolation polynomials (hereafter, the Hermite method). The requirements for the uncertainty of measurements carried out with the sensors of meteorological parameters, allowing to find the mean integral group refractive index of air, providing length measurements of the baselines of up to 5 km with an expanded uncertainty of not more than 1 mm, are established. Keywords: atmosphere; mean integral group refractive index of air; laser long distance measurement

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Distance measurement using the spherical wave fact of astronomical objects

Research Ideas and Outcomes ◽

10.3897/rio.6.e60713 ◽

2020 ◽

Vol 6 ◽

Author(s):

Yuanchuan Zou

Keyword(s):

Electromagnetic Waves ◽

Spherical Surface ◽

Spherical Wave ◽

Distance Measurement ◽

Independent Method ◽

Spherical Waves ◽

Position Accuracy ◽

Arduous Task ◽

Measurable Distance

Distance measurement is very important for astrophysics, and it is also an arduous task. Here we propose an independent method to measure the distances directly. Considering that electromagnetic waves are actually spherical waves from the source, people can get the distance of the source by accurately measuring the curvature of the spherical surface. The farthest measurable distance is roughly b2/b, where d is the separation of telescopes, and b is the position accuracy of the telescopes.

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Seti Space Missions

International Astronomical Union Colloquium ◽

10.1017/s0252921100015372 ◽

1997 ◽

Vol 161 ◽

pp. 761-776 ◽

Cited By ~ 1

Author(s):

Claudio Maccone

Keyword(s):

Electromagnetic Waves ◽

Space Missions ◽

Gravitational Lens ◽

The Sun ◽

Space Antenna ◽

Focal Distance ◽

Large Space ◽

The Earth ◽

Space Antennas ◽

New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

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Microwaves: Application in Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158248 ◽

1990 ◽

Vol 48 (3) ◽

pp. 140-141

Author(s):

Anthony S-Y Leong ◽

David W Gove

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Chemical Reactions ◽

Electromagnetic Waves ◽

Tissue Fixation ◽

Primary Method ◽

Dipolar Molecules ◽

Wide Range ◽

Time Required ◽

Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

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