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Journal articles on the topic 'Millimeter wave radars'

Author: Grafiati

Published: 28 June 2021

Last updated: 17 February 2022

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1

Essen, Helmut, Manfred Hägelen, Alfred Wahlen, Karsten Schulz, Klaus Jäger, and Marcus Hebel. "ISAR imaging of helicopters using millimeter wave radars." International Journal of Microwave and Wireless Technologies 1, no. 3 (June 2009): 171–78. http://dx.doi.org/10.1017/s1759078709000257.

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The capabilities of millimeter wave radars have been demonstrated for a long period of time for missile seeker applications and for automotive radars. The technological advantages of this type of radar can be adapted to security applications in air traffic management at short and medium range as well as on the ground. The application discussed in this paper focuses on inverse synthetic aperture radar (ISAR) imaging techniques for the derivation of high-resolution signatures of helicopters in the air and the determination of reference images using turntable measurements.

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2

Vavriv, D. M., V. A. Volkov, V. N. Bormotov, V. V. Vynogradov, R. V. Kozhyn, B. V. Trush, A. A. Belikov, and V. Ye Semenyuta. "Millimeter-Wave Radars for Environmental Studies." Telecommunications and Radio Engineering 61, no. 4 (2004): 292–313. http://dx.doi.org/10.1615/telecomradeng.v61.i4.30.

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3

Hogan, Robin J., Lin Tian, Philip R. A. Brown, Christopher D. Westbrook, Andrew J. Heymsfield, and Jon D. Eastment. "Radar Scattering from Ice Aggregates Using the Horizontally Aligned Oblate Spheroid Approximation." Journal of Applied Meteorology and Climatology 51, no. 3 (March 2012): 655–71. http://dx.doi.org/10.1175/jamc-d-11-074.1.

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AbstractThe assumed relationship between ice particle mass and size is profoundly important in radar retrievals of ice clouds, but, for millimeter-wave radars, shape and preferred orientation are important as well. In this paper the authors first examine the consequences of the fact that the widely used “Brown and Francis” mass–size relationship has often been applied to maximum particle dimension observed by aircraft Dmax rather than to the mean of the particle dimensions in two orthogonal directions Dmean, which was originally used by Brown and Francis. Analysis of particle images reveals that Dmax ≃ 1.25Dmean, and therefore, for clouds for which this mass–size relationship holds, the consequences are overestimates of ice water content by around 53% and of Rayleigh-scattering radar reflectivity factor by 3.7 dB. Simultaneous radar and aircraft measurements demonstrate that much better agreement in reflectivity factor is provided by using this mass–size relationship with Dmean. The authors then examine the importance of particle shape and fall orientation for millimeter-wave radars. Simultaneous radar measurements and aircraft calculations of differential reflectivity and dual-wavelength ratio are presented to demonstrate that ice particles may usually be treated as horizontally aligned oblate spheroids with an axial ratio of 0.6, consistent with them being aggregates. An accurate formula is presented for the backscatter cross section apparent to a vertically pointing millimeter-wave radar on the basis of a modified version of Rayleigh–Gans theory. It is then shown that the consequence of treating ice particles as Mie-scattering spheres is to substantially underestimate millimeter-wave reflectivity factor when millimeter-sized particles are present, which can lead to retrieved ice water content being overestimated by a factor of 4.

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4

Bhutani, Akanksha, Sören Marahrens, Michael Gehringer, Benjamin Göttel, Mario Pauli, and Thomas Zwick. "The Role of Millimeter-Waves in the Distance Measurement Accuracy of an FMCW Radar Sensor." Sensors 19, no. 18 (September 12, 2019): 3938. http://dx.doi.org/10.3390/s19183938.

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High-accuracy, short-range distance measurement is required in a variety of industrial applications e.g., positioning of robots in a fully automated production process, level measurement of liquids in small containers. An FMCW radar sensor is suitable for this purpose, since many of these applications involve harsh environments. Due to the progress in the field of semiconductor technology, FMCW radar sensors operating in different millimeter-wave frequency bands are available today. An important question in this context, which has not been investigated so far is how does a millimeter-wave frequency band influence the sensor accuracy, when thousands of distance measurements are performed with a sensor. This topic has been dealt with for the first time in this paper. The method used for analyzing the FMCW radar signal combines a frequency- and phase-estimation algorithm. The frequency-estimation algorithm based on the fast Fourier transform and the chirp-z transform provides a coarse estimate of the target distance. Subsequently, the phase-estimation algorithm based on a cross-correlation function provides a fine estimate of the target distance. The novel aspects of this paper are as follows. First, the estimation theory concept of Cramér-Rao lower bound (CRLB) has been used to compare the accuracy of two millimeter-wave FMCW radars operating at 60 GHz and 122 GHz. In this comparison, the measurement parameters (e.g., bandwidth, signal-to-noise ratio) as well as the signal-processing algorithm used for both the radars are the same, thus ensuring an unbiased comparison of the FMCW radars, solely based on the choice of millimeter-wave frequency band. Second, the improvement in distance measurement accuracy obtained after each step of the combined frequency- and phase-estimation algorithm has been experimentally demonstrated for both the radars. A total of 5100 short-range distance measurements are made using the 60 GHz and 122 GHz FMCW radar. The measurement results are analyzed at various stages of the frequency- and phase-estimation algorithm and the measurement error is calculated using a nanometer-precision linear motor. At every stage, the mean error values measured with the 60 GHz and 122 GHz FMCW radars are compared. The final accuracy achieved using both radars is of the order of a few micrometers. The measured standard deviation values of the 60 GHz and 122 GHz FMCW radar have been compared against the CRLB. As predicted by the CRLB, this paper experimentally validates for the first time that the 122 GHz FMCW radar provides a higher repeatability of micrometer-accuracy distance measurements than the 60 GHz FMCW radar.

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5

Antolinos, Elías, Federico García-Rial, Clara Hernández, Daniel Montesano, Juan I. Godino-Llorente, and Jesús Grajal. "Cardiopulmonary Activity Monitoring Using Millimeter Wave Radars." Remote Sensing 12, no. 14 (July 15, 2020): 2265. http://dx.doi.org/10.3390/rs12142265.

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Current cardiopulmonary activity monitoring is based on contact devices which cannot be used in extreme cases such as premature infants, burnt victims or rescue operations. In order to overcome these limitations, the use of radar technologies emerges as an alternative. This paper aims to enhance the comprehension that non-contact technologies, in particular radar techniques, offer as a monitoring tool. For this purpose, a modified low cost commercial 122 GHz frequency-modulated continuous-wave (FMCW) radar is used to better fit the current application domain. The radar signals obtained are processed using a classic linear filtering algorithm aiming to separate the breathing from the heartbeat component while preserving signals integrity. In a standoff configuration and with different subject orientations, results show that the signal obtained with the radar can be used to extract not only the respiratory and heartbeat rates, but also the heart rate variability (HRV) sequence. Moreover, results evidence the coupling between breathing and heartbeat, also showing that the HRV sequence obtained can identify the respiratory sinus arrhythmia (RSA) effect. Finally, the radar is tested in a simultaneous multi-target scenario, demonstrating its monitoring capabilities in more complex situations. Nevertheless, there are some challenges left to use the system in a real-life monitoring environments, such as the removal of random body movements.

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6

Abdu, Fahad Jibrin, Yixiong Zhang, Maozhong Fu, Yuhan Li, and Zhenmiao Deng. "Application of Deep Learning on Millimeter-Wave Radar Signals: A Review." Sensors 21, no. 6 (March 10, 2021): 1951. http://dx.doi.org/10.3390/s21061951.

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The progress brought by the deep learning technology over the last decade has inspired many research domains, such as radar signal processing, speech and audio recognition, etc., to apply it to their respective problems. Most of the prominent deep learning models exploit data representations acquired with either Lidar or camera sensors, leaving automotive radars rarely used. This is despite the vital potential of radars in adverse weather conditions, as well as their ability to simultaneously measure an object’s range and radial velocity seamlessly. As radar signals have not been exploited very much so far, there is a lack of available benchmark data. However, recently, there has been a lot of interest in applying radar data as input to various deep learning algorithms, as more datasets are being provided. To this end, this paper presents a survey of various deep learning approaches processing radar signals to accomplish some significant tasks in an autonomous driving application, such as detection and classification. We have itemized the review based on different radar signal representations, as it is one of the critical aspects while using radar data with deep learning models. Furthermore, we give an extensive review of the recent deep learning-based multi-sensor fusion models exploiting radar signals and camera images for object detection tasks. We then provide a summary of the available datasets containing radar data. Finally, we discuss the gaps and important innovations in the reviewed papers and highlight some possible future research prospects.

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7

Levy, Chagai, Monika Pinchas, and Yosef Pinhasi. "Coherent Integration Loss Due to Nonstationary Phase Noise in High-Resolution Millimeter-Wave Radars." Remote Sensing 13, no. 9 (April 30, 2021): 1755. http://dx.doi.org/10.3390/rs13091755.

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Phase noise refers to the instability of an oscillator, which is the cause of instantaneous phase and frequency deviations in the carrier wave. This unavoidable instability adversely affects the performance of range–velocity radar systems, including synthetic aperture radars (SARs) and ground-moving target indicator (GMTI) radars. Phase noise effects should be considered in high-resolution radar designs, operating in millimeter wavelengths and terahertz frequencies, due to their role in radar capability during the reliable identification of target location and velocity. In general, phase noise is a random process consisting of nonstationary terms. It has been shown that in order to optimize the coherent detection of stealthy, fast-moving targets with a low radar cross-section (RCS), it is required to evaluate the integration gain and to determine the incoherent noise effects for resolving target location and velocity. Here, we present an analytical expression for the coherent integration loss when a nonstationary phase noise is considered. A Wigner distribution was employed to derive the time–frequency expression for the coherent loss when nonstationary conditions were considered. Up to now, no analytical expressions have been developed for coherent integration loss when dealing with real nonstationary phase noise mathematical models. The proposed expression will help radar systems estimate the nonstationary integration loss and adjust the decision threshold value in order to maximize the probability of detection. The effect of nonstationary phase noise is demonstrated for studying coherent integration loss of high-resolution radar operating in the W-band. The investigation indicates that major degradation in the time-frequency coherent integration due to short-term, nonstationary phase noise instabilities arises for targets moving at low velocities and increases with range. Opposed to the conventional model, which assumes stationarity, a significant difference of up to 25 dB is revealed in the integration loss for radars operating in the millimeter wave regime. Moreover, for supersonic moving targets, the loss peaks at intermediate distances and then reduces as the target moves away.

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8

Kutsov, Vladimir, Vladimir Badenko, Sergey Ivanov, and Alexander Fedotov. "Millimeter Wave Radar for Intelligent Transportation Systems: a Case Study of Multi-Target Problem Solution." E3S Web of Conferences 157 (2020): 05011. http://dx.doi.org/10.1051/e3sconf/202015705011.

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The influence of millimeter-wave radar receiver noise on the probability of unambiguous determination of unmanned vehicles speed and range in the intelligent transportation system of the «smart city» is investigated. For the proposed new multi-target detection method for FMCW radar, the effect of the technical parameters of the vehicle radars on the required signal-to-noise ratio (SNR) of the receiver is estimated to ensure the probability of true determination of target parameters at 98%.

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9

Pan, Mingming, Adrien Chopard, Frederic Fauquet, Patrick Mounaix, and Jean-Paul Guillet. "Guided Reflectometry Imaging Unit Using Millimeter Wave FMCW Radars." IEEE Transactions on Terahertz Science and Technology 10, no. 6 (November 2020): 647–55. http://dx.doi.org/10.1109/tthz.2020.3008330.

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10

Gonzalez-Partida, J. T., P. Almorox-Gonzalez, M. Burgos-Garcia, B. P. Dorta-Naranjo, and J. I. Alonso. "Through-the-Wall Surveillance With Millimeter-Wave LFMCW Radars." IEEE Transactions on Geoscience and Remote Sensing 47, no. 6 (June 2009): 1796–805. http://dx.doi.org/10.1109/tgrs.2008.2007738.

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11

Mead, J. B., A. L. Pazmany, S. M. Sekelsky, and R. E. McIntosh. "Millimeter-wave radars for remotely sensing clouds and precipitation." Proceedings of the IEEE 82, no. 12 (1994): 1891–906. http://dx.doi.org/10.1109/5.338077.

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12

Bureneva, O. I., I. G. Gorbunov, G. V. Komarov, A. A. Konovalov, M. S. Kupriyanov, and Yu A. Shichkina. "A Prototype of Automotive 77 GHz Radar." Journal of the Russian Universities. Radioelectronics 24, no. 3 (June 24, 2021): 22–38. http://dx.doi.org/10.32603/1993-8985-2021-24-3-22-38.

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Introduction. Automotive radars are the main tools for providing traffic safety. The development of such radars involve a number of technical difficulties due to the manufacture of high-precision extremely high-frequency (EHF) printed circuit boards. To facilitate the process of creating such devices, the existing algorithms for radar information processing should be debugged using prototypes from manufacturers of mm-band transceivers. However, the parameters of such boards are not known in advance, and the actual operating conditions of the as-produced automotive radars raise new challenges to target tracking algorithms. Therefore, checking the performance of such boards is a relevant research problem.Aim. To evaluate the performance of a millimeter-wave automotive radar prototype and to test target tracking algorithms using this prototype.Materials and methods. An original target tracking method was used, which considers the constraints on the use of additional data sources about the radar carrier movement.Results. An experimental performance evaluation of a 77 GHz automotive radar prototype was carried out. The effectiveness of primary processing for the target class “vehicle” in the millimetre range was checked. Original algorithms for target tracking were proposed and tested.Conclusion. The obtained results show that the prototype board of a transceiver chip is capable of testing tracking algorithms without creating an own automotive radar prototype. Thus, the developmental process can be significantly shortened. Moreover, after creating a hardware solution, the developer obtains a reference device to test and configure an own product without using extremely expensive and rare EHF equipment.

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13

Kui, Liping, Sai Huang, and Zhiyong Feng. "Interference Analysis for mmWave Automotive Radar Considering Blockage Effect." Sensors 21, no. 12 (June 8, 2021): 3962. http://dx.doi.org/10.3390/s21123962.

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Due to the increasing number of vehicles equipped with millimeter wave (mmWave) radars, interference among automotive radars is becoming a major issue. This paper explores the automotive radar interference in both two-lane and multi-lane scenarios using stochastic geometry. We derive closed-form expressions for mean and variance of interference power considering directional antenna with constant and Gaussian decaying gains. In view of the sensitivity of mmWave radar signals to the blockages, we propose a blockage model including partially and completely blocking, and then calculate the effective number of the interferers. By means of modeling randomness for interferers and blockages as Poisson point process, we characterize the statistics of radar interference under different conditions. We further utilize the interference characterization to estimate the successful ranging probability of automotive radars. These theoretical analyses are verified by using Monte Carlo simulations. The results show that the increasing interfering density and ranging distance largely degrade the radar detection performance, whereas the interference levels decrease as blockage intensity increases.

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14

Omer, Ala Eldin, Safieddin Safavi-Naeini, Richard Hughson, and George Shaker. "Blood Glucose Level Monitoring Using an FMCW Millimeter-Wave Radar Sensor." Remote Sensing 12, no. 3 (January 25, 2020): 385. http://dx.doi.org/10.3390/rs12030385.

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In this article, a novel sensing approach is presented for glucose level monitoring where a robust low-power millimeter(mm)-wave radar system is used to differentiate between blood samples of disparate glucose concentrations in the range 0.5 to 3.5 mg/mL. The proposed radar sensing mechanism shows greater capabilities for remote detection of blood glucose inside test tubes through detecting minute changes in their dielectric properties. In particular, the reflected mm-waves that represent unique signatures for the internal synthesis and composition of the tested blood samples, are collected from the multi-channels of the radar and analyzed using signal processing techniques to identify different glucose concentrations and correlate them to the reflected mm-wave readings. The mm-wave spectrum is chosen for glucose sensing in this study after a set of preliminary experiments that investigated the dielectric permittivity behavior of glucose-loaded solutions across different frequency bands. In this regard, a newly-developed commercial coaxial probe kit (DAK-TL) is used to characterize the electromagnetic properties of glucose-loaded samples in a broad range of frequencies from 300 MHz to 67 GHz using two different 50 Ω open-coaxial probes. This would help to determine the portion of the frequency spectrum that is more sensitive to slight variations in glucose concentrations as indicated by the amount of change in the dielectric constant and loss tangent parameters due to the different concentrations under test. The mm-wave frequency range 50 to 67 GHz has shown to be promising for acquiring both high sensitivity and sufficient penetration depth for the most interaction between the glucose molecules and electromagnetic waves. The processed results have indicated the reliability of using mm-wave radars in identifying changes in blood glucose levels while monitoring trends among those variations. Particularly, blood samples of higher glucose concentrations are correlated with reflected mm-wave signals of greater energy. The proposed system could likely be adapted in the future as a portable non-invasive continuous blood glucose level monitoring for daily use by diabetics.

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15

Cui, Han, and Naim Dahnoun. "High Precision Human Detection and Tracking Using Millimeter-Wave Radars." IEEE Aerospace and Electronic Systems Magazine 36, no. 1 (January 1, 2021): 22–32. http://dx.doi.org/10.1109/maes.2020.3021322.

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16

Heddebaut, Marc, Fouzia Elbahhar, Christophe Loyez, Nizar Obeid, Nathalie Rolland, Atika Rivenq, and Jean-Michel Rouvaen. "Millimeter-wave communicating-radars for enhanced vehicle-to-vehicle communications." Transportation Research Part C: Emerging Technologies 18, no. 3 (June 2010): 440–56. http://dx.doi.org/10.1016/j.trc.2009.05.004.

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17

Aghasi, Hamidreza, and Payam Heydari. "Millimeter-Wave Radars-on-Chip Enabling Next-Generation Cyberphysical Infrastructures." IEEE Communications Magazine 58, no. 12 (December 2020): 70–76. http://dx.doi.org/10.1109/mcom.001.2000544.

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18

Manheimer, Wallace M. "Application of gyrotrons to high power millimeter wave Doppler radars." International Journal of Infrared and Millimeter Waves 13, no. 10 (October 1992): 1449–57. http://dx.doi.org/10.1007/bf01009229.

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Cui, Han, and Naim Dahnoun. "High Precision Human Detection and Tracking Using Millimeter-Wave Radars." IEEE Aerospace and Electronic Systems Magazine 36, no. 1 (January 1, 2021): 22–32. http://dx.doi.org/10.1109/maes.2020.3021322.

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20

Rapaport, Liat, Ariel Etinger, Boris Litvak, Gad Pinhasi, and Yosef Pinhasi. "Quasi Optical Multi-Ray Model For Wireless Communication Link in Millimeter Wavelengths." MATEC Web of Conferences 210 (2018): 03006. http://dx.doi.org/10.1051/matecconf/201821003006.

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The spectrum of millimeter waves lay above 30GHz. The band between 30GHz up to 300GHz is called Extremely High Frequencies (EHF). This wide spectrum is relatively free of users and have recently became relevant for realizations of wireless communications an radars, including the fifth generation (5G) of cellular communications. Due to the short wavelengths, the propagation of millimeter waves can be analyzed using quasi-optical ray techniques. We present a multi-ray analysis of millimeter wave wireless link in the presence of multipath. The analysis is applicable for indoor and outdoor links and considers reflections from walls and buildings. It is shown that line-of-sight is not necessarily required in scenarios where multiple reflections exist as in long corridors, canyons and tunnels. The theoretical results are verified experimentally with a link in the W-band (94GHz).

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21

Milovanovic, Vladimir. "On fundamental operating principles and range-doppler estimation in monolithic frequency-modulated continuous-wave radar sensors." Facta universitatis - series: Electronics and Energetics 31, no. 4 (2018): 547–70. http://dx.doi.org/10.2298/fuee1804547m.

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The diverse application areas of emerging monolithic noncontact radar sensors that are able to measure object?s distance and velocity is expected to grow in the near future to scales that are now nearly inconceivable. A classical concept of frequency-modulated continuous-wave (FMCW) radar, tailored to operate in the millimeter-wave (mm-wave) band, is well-suited to be implemented in the baseline CMOS or BiCMOS process technologies. High volume production could radically cut the cost and decrease the form factor of such sensing devices thus enabling their omnipresence in virtually every field. This introductory paper explains the key concepts of mm-wave sensing starting from a chirp as an essential signal in linear FMCW radars. It further sketches the fundamental operating principles and block structure of contemporary fully integrated homodyne FMCW radars. Crucial radar parameters like the maximum unambiguously measurable distance and speed, as well as range and velocity resolutions are specified and derived. The importance of both beat tones in the intermediate frequency (IF) signal and the phase in resolving small spatial perturbations and obtaining the 2-D range-Doppler plot is pointed out. Radar system-level trade-offs and chirp/frame design strategies are explained. Finally, the nonideal and second-order effects are commented and the examples of practical FMCW transmitter and receiver implementations are summarized.

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Valuyskiy, D. V., A. A. Panarina, S. V. Vityazev, and V. V. Vityazev. "Test bench development for signal registration in millimeter wave automotive radars." IOP Conference Series: Materials Science and Engineering 534 (June 5, 2019): 012020. http://dx.doi.org/10.1088/1757-899x/534/1/012020.

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23

Guidi, Francesco, Anna Guerra, and Davide Dardari. "Personal Mobile Radars with Millimeter-Wave Massive Arrays for Indoor Mapping." IEEE Transactions on Mobile Computing 15, no. 6 (June 1, 2016): 1471–84. http://dx.doi.org/10.1109/tmc.2015.2467373.

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24

Sekelsky, Stephen M., and Eugene E. Clothiaux. "Parallax Errors and Corrections for Dual-Antenna Millimeter-Wave Cloud Radars." Journal of Atmospheric and Oceanic Technology 19, no. 4 (April 2002): 478–85. http://dx.doi.org/10.1175/1520-0426(2002)019<0478:peacfd>2.0.co;2.

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Jain, Vipul, Babak Javid, and Payam Heydari. "A BiCMOS Dual-Band Millimeter-Wave Frequency Synthesizer for Automotive Radars." IEEE Journal of Solid-State Circuits 44, no. 8 (August 2009): 2100–2113. http://dx.doi.org/10.1109/jssc.2009.2022299.

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26

Moosavifar, Milad, and David Wentzloff. "A High Gain Lens-Coupled On-Chip Antenna Module for Miniature-Sized Millimeter-Wave Wireless Transceivers." Applied Computational Electromagnetics Society 35, no. 11 (February 5, 2021): 1380–81. http://dx.doi.org/10.47037/2020.aces.j.351159.

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This paper presents high gain and compact Transmit/Receive (TX/RX) integrated antennas in a standard BiCMOS 130nm technology for millimeter-scale millimeter-wave (mm-wave) applications, including high data rate radios and high resolution radars. The proposed TX/RX antenna module utilizes an integrated dipole antenna for the receiver and a slot antenna for the transmitter, placed orthogonally. The achieved gain and radiation efficiency are 5.7dBi and 41.3% for the slot antenna, respectively, and 6dBi and 39% for the dipole antenna. The link budget is improved by 16dB by optimization on the geometry as well as application of a high resistivity hemispheric silicon dielectric lens.

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Wada, Eiko, Hiroyuki Hashiguchi, Masayuki K. Yamamoto, Michihiro Teshiba, and Shoichiro Fukao. "Simultaneous Observations of Cirrus Clouds with a Millimeter-Wave Radar and the MU Radar." Journal of Applied Meteorology 44, no. 3 (March 1, 2005): 313–23. http://dx.doi.org/10.1175/jam2191.1.

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Abstract Observations of frontal cirrus clouds were conducted with the scanning millimeter-wave radar at the Shigaraki Middle and Upper Atmosphere (MU) Radar Observatory in Shiga, Japan, during 30 September–13 October 2000. The three-dimensional background winds were also observed with the very high frequency (VHF) band MU radar. Comparing the observational results of the two radars, it was found that the cirrus clouds appeared coincident with the layers of the strong vertical shear of the horizontal winds, and they developed and became thicker under the condition of the strong vertical shear of the horizontal wind and updraft. The result of the radiosonde observation indicated that Kelvin–Helmholtz instability (KHI) occurred at 8–9-km altitudes because of the strong vertical shear of the horizontal wind. The warm and moist air existed above the 8.5-km altitude, and the cold and dry air existed below the 8.5-km altitude. As a result of the airmass mixing of air above and below the 8.5-km altitudes, the cirrus clouds were formed. The updraft, which existed at 8.5–12-km altitude, caused the development of the cirrus clouds with the thickness of >2 km. By using the scanning millimeter-wave radar, the three-dimensional structure of cell echoes formed by KHI for the first time were successfully observed.

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Melezhik, Peter, Vadim Razskazovskiy, Nikolay Reznichenko, Vladimir Zuykov, Аnton Varavin, Yury Sidorenko, and Felix Yanovsky. "HIGH-EFFICIENCY MILLIMETER-WAVE COHERENT RADAR FOR AIRPORT SURFACE MOVEMENT MONITORING AND CONTROL / DIDELIO EFEKTYVUMO MILIMETRINIO DIAPAZONO KOHERENTINIS RADIOLOKATORIUS MONITORINGUI IR ANTŽEMINIO JUDĖJIMO VALDYMUI ORO UOSTUOSE." Aviation 15, no. 2 (May 24, 2011): 38–43. http://dx.doi.org/10.3846/16487788.2011.596673.

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The paper outlines the operation principles, technical characteristics and the field test results of the innovative Ka-band radar for airport surface monitoring. Advantages and disadvantages of operation in the Ka-band with respect to a shorter one, i.e. The W-band, are discussed. It is shown that in the Ka-band the coherent operation mode can be realized. This mode enables one not only to essentially reduce the radiation power to the level provided by the available semiconductor devices, but also to perform moving target detection on interference created by reflections from surface objects and rain as well as to perform automatic classification of targets according to their radial velocity of movement. Main performance specifications, principle of operation, and design of the innovative antenna developed for the radar are described in detail. The results of the field tests confirm the predicted radar operation characteristics. The radars of the proposed type can be used as radar-sensors for systems of airport surface monitoring. Santrauka Straipsnyje aprašyti naujo koherentinio radaro darbo principai, techninės charakteristikos ir lauko bandymų skrydžių lauko apžvalgai 8 mm diapazonu rezultatai, palygintos 8 mm sistemų ir jų trumpabangių analogų charakteristikos. Parodyta, kaip galima taikyti koherentinį režimą. Toks darbo režimas leidžia ne tik sumažinti išspinduliuojamą radaro energiją iki šiuolaikine puslaidininkių įranga sukuriamo lygio. Koherentinis režimas leidžia atlikti judančių objektų doplerinę selekciją stiprių atspindžių nuo stacionarių objektų ir kritulių sąlygomis. Tai leidžia klasifikuoti tikslus pagal greičio požymius. Aprašomi pagrindiniai parametrai, veikimo principai, šiam radarui sukurtos antenos sandara. Lauko bandymų rezultatai rodo, kad sistema sutampa su pasirinktais parametrais. Pasiūlytas radaras gali būti naudojamas skrydžių lauko apžvalgos sistemose.

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Li, Lihua, Gerald M. Heymsfield, Lin Tian, and Paul E. Racette. "Measurements of Ocean Surface Backscattering Using an Airborne 94-GHz Cloud Radar—Implication for Calibration of Airborne and Spaceborne W-Band Radars." Journal of Atmospheric and Oceanic Technology 22, no. 7 (July 1, 2005): 1033–45. http://dx.doi.org/10.1175/jtech1722.1.

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Abstract Backscattering properties of the ocean surface have been widely used as a calibration reference for airborne and spaceborne microwave sensors. However, at millimeter-wave frequencies, the ocean surface backscattering mechanism is still not well understood, in part, due to the lack of experimental measurements. During the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE), measurements of ocean surface backscattering were made using a 94-GHz (W band) cloud radar on board a NASA ER-2 high-altitude aircraft. This unprecedented dataset enhances our knowledge about the ocean surface scattering mechanism at 94 GHz. The measurement set includes the normalized ocean surface cross section over a range of the incidence angles under a variety of wind conditions. It was confirmed that even at 94 GHz, the normalized ocean surface radar cross section, σo, is insensitive to surface wind conditions near a 10° incidence angle, a finding similar to what has been found in the literature for lower frequencies. Analysis of the radar measurements also shows good agreement with a quasi-specular scattering model at low incidence angles. The results of this work support the proposition of using the ocean surface as a calibration reference for airborne millimeter-wave cloud radars and for the ongoing NASA CloudSat mission, which will use a 94-GHz spaceborne cloud radar for global cloud measurements.

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Ciattaglia, Gianluca, Adelmo De Santis, Deivis Disha, Susanna Spinsante, Paolo Castellini, and Ennio Gambi. "Performance Evaluation of Vibrational Measurements through mmWave Automotive Radars." Remote Sensing 13, no. 1 (December 30, 2020): 98. http://dx.doi.org/10.3390/rs13010098.

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Thanks to the availability of a significant amount of inexpensive commercial Frequency Modulated Continuous Wave Radar sensors, designed primarily for the automotive domain, it is interesting to understand if they can be used in alternative applications. It is well known that with a radar system it is possible to identify the micro-Doppler feature of a target, to detect the nature of the target itself (what the target is) or how it is vibrating. In fact, thanks to their high transmission frequency, large bandwidth and very short chirp signals, radars designed for automotive applications are able to provide sub-millimeter resolution and a large detection bandwidth, to the point that it is here proposed to exploit them in the vibrational analysis of a target. The aim is to evaluate what information on the vibrations can be extracted, and what are the performance obtainable. In the present work, the use of a commercial Frequency Modulated Continuous Wave radar is described, and the performances achieved in terms of displacement and vibration frequency measurement of the target are compared with the measurement results obtained through a laser vibrometer, considered as the reference instrument. The attained experimental results show that the radar under test and the reference laser vibrometer achieve comparable outcomes, even in a cluttered scenario.

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Almorox-Gonzalez, P., J. T. Gonzalez-Partida, M. Burgos-Garcia, B. P. Dorta-Naranjo, and J. Gismero. "Millimeter-Wave Sensor With FMICW Capabilities for Medium-Range High-Resolution Radars." IEEE Transactions on Microwave Theory and Techniques 57, no. 6 (June 2009): 1479–86. http://dx.doi.org/10.1109/tmtt.2009.2019991.

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Stephens, Graeme L., and Norman B. Wood. "Properties of Tropical Convection Observed by Millimeter-Wave Radar Systems." Monthly Weather Review 135, no. 3 (March 1, 2007): 821–42. http://dx.doi.org/10.1175/mwr3321.1.

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Abstract This paper describes the results of analysis of over 825 000 profiles of millimeter-wave radar (MWR) reflectivities primarily collected by zenith-pointing surface radars observing tropical convection associated with various phases of activity of the large-scale tropical circulation. The data principally analyzed in this paper come from surface observations obtained at the Atmospheric Radiation Measurement Manus site during active and break episodes of the Madden–Julian oscillation (MJO) and from observations collected from a shipborne radar during an active phase of the monsoon over the Indian Ocean during the Joint Air–Sea Monsoon Interaction Experiment. It was shown, for example, in a histogram regime analysis that the MWR data produce statistics on convection regimes similar in most respects to the analogous regime analysis of the Tropical Rainfall Measuring Mission radar–radiometer observations. Attenuation of the surface MWRs by heavy precipitation, however, incorrectly shifts a small fraction of the deeper precipitation modes into the shallow modes of precipitation. The principal findings are the following. (i) The cloud and precipitation structures of the different convective regimes are largely identical regardless of the mode of synoptic forcing, that is, regardless of whether the convection occurred during an active phase of the MJO, a transition phase of the MJO, or in an active monsoon period. What changes between these synoptically forced modes of convection are the relative frequencies of occurrences of the different storm regimes. (ii) The cloud structures associated with the majority of cases of observed precipitation (ranging in occurrence from 45% to 53% of all precipitation profiles) were multilayered structures regardless of the mode of synoptic forcing. The predominant multilayered cloud mode was of higher-level cirrus of varying thickness overlying cumulus congestus–like convection. (iii) The majority of water accumulated (i.e., 53%–63%) over each of the periods assigned to the active monsoon (5 days of data), the active MJO (38 days of data), and the transition MJO (53 days of data) fell from these multiple-layered cloud systems. (iv) Solar transmittances reveal that significantly less sunlight (reductions of about 30%–50%) reaches the surface in the precipitating regimes than reaches the surface under drizzle and cloud-only conditions, suggesting that the optical thicknesses of precipitation-bearing clouds significantly exceeds those of nonprecipitating clouds.

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Díez-Pastor, José Francisco, Pedro Latorre-Carmona, José Luis Garrido-Labrador, José Miguel Ramírez-Sanz, and Juan J. Rodríguez. "Experimental Assessment of Feature Extraction Techniques Applied to the Identification of Properties of Common Objects, Using a Radar System." Applied Sciences 11, no. 15 (July 22, 2021): 6745. http://dx.doi.org/10.3390/app11156745.

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Radar technology has evolved considerably in the last few decades. There are many areas where radar systems are applied, including air traffic control in airports, ocean surveillance, and research systems, to cite a few. Other types of sensors have recently appeared, which allow tracking sub-millimeter motion with high speed and accuracy rates. These millimeter-wave radars are giving rise to myriad new applications, from the recognition of the material close objects are made, to the recognition of hand gestures. They have also been recently used to identify how a person interacts with digital devices through the physical environment (Tangible User Interfaces, TUIs). In this case, the radar is used to detect the orientation, movement, or distance from the objects to the user’s hands or the digital device. This paper presents a thoughtful comparative analysis of different feature extraction techniques and classification strategies applied on a series of datasets that cover problems such as the identification of materials, element counting, or determining the orientation and distance of objects to the sensor. The results outperform previous works using these datasets, especially when the accuracy was lowest, showing the benefits feature extraction techniques have on classification performance.

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Dumbrajs, Olgerts. "ELECTRON TRAJECTORIES IN A REALISTIC GYROTRON RESONATOR." Mathematical Modelling and Analysis 3, no. 1 (December 15, 1998): 74–80. http://dx.doi.org/10.3846/13926292.1998.9637088.

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Gyrotron is a special tube generating powerful radiowaves in the millimeter wave range. Gyrotrons are mainly used to heat nuclear fusion plasma, in order to induce controlled thermonuclear reactions on earth. In addition, they have found a wide utility in radars and the high‐temperature processing of materials. Differential equations describing gyrotron operation are analyzed from the mathematical point of view. Phase portraits of electron trajectories in realistic resonators are determined.

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Sekelsky, Stephen M. "Near-Field Reflectivity and Antenna Boresight Gain Corrections for Millimeter-Wave Atmospheric Radars." Journal of Atmospheric and Oceanic Technology 19, no. 4 (April 2002): 468–77. http://dx.doi.org/10.1175/1520-0426(2002)019<0468:nfraab>2.0.co;2.

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Vasanelli, Claudia, Fabian Roos, Andre Durr, Johannes Schlichenmaier, Philipp Hugler, Benedikt Meinecke, Maximilian Steiner, and Christian Waldschmidt. "Calibration and Direction-of-Arrival Estimation of Millimeter-Wave Radars: A Practical Introduction." IEEE Antennas and Propagation Magazine 62, no. 6 (December 2020): 34–45. http://dx.doi.org/10.1109/map.2020.2988528.

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Essen, Helmut, Wolfgang Koch, Sebastian Hantscher, Rüdiger Zimmermann, Paul Warok, Martin Schröder, Marek Schikora, and Goert Luedtke. "A multimodal sensor system for runway debris detection." International Journal of Microwave and Wireless Technologies 4, no. 2 (April 2012): 155–62. http://dx.doi.org/10.1017/s1759078712000116.

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For foreign object detection on runways, highly sensitive radar sensors give the opportunity to detect even very small objects, metallic and non-metallic, also under adverse weather conditions. As it is desirable for airport applications to install only small but robust installations along the traffic areas, millimeter-wave radars offer the advantage of small antenna apertures and miniaturized system hardware. A 220-GHz radar was developed, which is capable to serve this application, if several of these are netted to cover the whole traffic area. Although under fortunate conditions the radar allows a classification or even an identification of the debris, the complete system design incorporates 3-D time-of-flight cameras for assistance in the identification process, which are also distributed along the traffic areas. The system approach further relies upon a change detection algorithm on the netted information to discriminate non-stationary alarms and reduce the false alarm ratio.

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Weidinger, C., T. Kadiofsky, P. Glira, C. Zinner, and W. Kubinger. "3D ONLINE TERRAIN MAPPING WITH SCANNING RADAR SENSORS." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences V-1-2020 (August 3, 2020): 125–32. http://dx.doi.org/10.5194/isprs-annals-v-1-2020-125-2020.

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Abstract. Environmental perception is one of the core requirements in autonomous vehicle navigation. If exposed to harsh conditions, commonly deployed sensors like cameras or lidars deliver poor sensing performance. Millimeter wave radars enable robust sensing of the environment, but suffer from specular reflections and large beamwidths. To incorporate the sensor noise and lateral uncertainty, a new probabilistic, voxel-based recursive mapping method is presented to enable online terrain mapping using scanning radar sensors. For map accuracy evaluation, test measurements are performed with a scanning radar sensor in an off-road area. The voxel map is used to derive a digital terrain model, which can be compared with ground-truth data from an image-based photogrammetric reconstruction of the terrain. The method evaluation shows promising results for terrain mapping solely performed with radar scanners. However, small terrain structures still pose a problem due to larger beamwidths in comparison to lidar sensors.

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Sokolov, Andrei Vladimirovich, Yurii Vasilievich Opalenov, and Aleksander Alekseevich Potapov. "Digital Coherent Radars with a Composite Signal in the Centimeter and Millimeter Wave Ranges." Telecommunications and Radio Engineering 54, no. 7 (2000): 86–91. http://dx.doi.org/10.1615/telecomradeng.v54.i7.90.

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Bai, Jie, Lianqing Zheng, Sen Li, Bin Tan, Sihan Chen, and Libo Huang. "Radar Transformer: An Object Classification Network Based on 4D MMW Imaging Radar." Sensors 21, no. 11 (June 2, 2021): 3854. http://dx.doi.org/10.3390/s21113854.

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Automotive millimeter-wave (MMW) radar is essential in autonomous vehicles due to its robustness in all weather conditions. Traditional commercial automotive radars are limited by their resolution, which makes the object classification task difficult. Thus, the concept of a new generation of four-dimensional (4D) imaging radar was proposed. It has high azimuth and elevation resolution and contains Doppler information to produce a high-quality point cloud. In this paper, we propose an object classification network named Radar Transformer. The algorithm takes the attention mechanism as the core and adopts the combination of vector attention and scalar attention to make full use of the spatial information, Doppler information, and reflection intensity information of the radar point cloud to realize the deep fusion of local attention features and global attention features. We generated an imaging radar classification dataset and completed manual annotation. The experimental results show that our proposed method achieved an overall classification accuracy of 94.9%, which is more suitable for processing radar point clouds than the popular deep learning frameworks and shows promising performance.

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Chimeh, Jahangir Dadkhah, Saeed Bashirzadeh Parapari, and Seyed Mohmoud Mousavinejad. "Millimetric Waves Technologies: Opportunities and Challenges." Key Engineering Materials 500 (January 2012): 263–68. http://dx.doi.org/10.4028/www.scientific.net/kem.500.263.

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Providing an available wideband and better antenna beam forming are two good profits of millimeter wave (mmWave) technology. MmWave technology makes radio systems lighter and smaller and radars more precise. Today, commercial MmWave equipment work below 90GHz frequencies. MmWave radios work to transport Internat traffic in the backhaul of communication networks. There is a challenge in mmWave technology since the prices of equipment increases as the frequency increases. In this paper we study the applications of mmWave technology, its products, standards and compare it with other wireless technologies.

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Guidi, Francesco, Anna Guerra, and Davide Dardari. "Comments on the Paper “Personal Mobile Radars with Millimeter-Wave Massive Arrays for Indoor Mapping”." IEEE Transactions on Mobile Computing 16, no. 6 (June 1, 2017): 1786. http://dx.doi.org/10.1109/tmc.2017.2680778.

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Zhou, Taohua, Mengmeng Yang, Kun Jiang, Henry Wong, and Diange Yang. "MMW Radar-Based Technologies in Autonomous Driving: A Review." Sensors 20, no. 24 (December 18, 2020): 7283. http://dx.doi.org/10.3390/s20247283.

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With the rapid development of automated vehicles (AVs), more and more demands are proposed towards environmental perception. Among the commonly used sensors, MMW radar plays an important role due to its low cost, adaptability In different weather, and motion detection capability. Radar can provide different data types to satisfy requirements for various levels of autonomous driving. The objective of this study is to present an overview of the state-of-the-art radar-based technologies applied In AVs. Although several published research papers focus on MMW Radars for intelligent vehicles, no general survey on deep learning applied In radar data for autonomous vehicles exists. Therefore, we try to provide related survey In this paper. First, we introduce models and representations from millimeter-wave (MMW) radar data. Secondly, we present radar-based applications used on AVs. For low-level automated driving, radar data have been widely used In advanced driving-assistance systems (ADAS). For high-level automated driving, radar data is used In object detection, object tracking, motion prediction, and self-localization. Finally, we discuss the remaining challenges and future development direction of related studies.

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Hogan, Robin J., Nicolas Gaussiat, and Anthony J. Illingworth. "Stratocumulus Liquid Water Content from Dual-Wavelength Radar." Journal of Atmospheric and Oceanic Technology 22, no. 8 (August 1, 2005): 1207–18. http://dx.doi.org/10.1175/jtech1768.1.

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Abstract A technique is described to retrieve stratocumulus liquid water content (LWC) using the differential attenuation measured by vertically pointing radars at 35 and 94 GHz. Millimeter-wave attenuation is proportional to LWC and increases with frequency, so LWC can be derived without the need to make any assumptions on the nature of the droplet size distribution. There is also no need for the radars to be well calibrated. A significant advantage over many radar techniques in stratocumulus is that the presence of drizzle drops (those with a diameter larger than around 50 μm) does not affect the retrieval, even though such drops may dominate the radar signal. It is important, however, that there are not significant numbers of drops larger than 600 μm, which scatter outside of the Rayleigh regime at 94 GHz. A lidar ceilometer is used to locate the cloud base in the presence of drizzle falling below the cloud. An accuracy of around 0.04 g m−3 is achievable with averaging over 1 min and 150 m (two range gates), but for the previously suggested frequency pair of 10 and 35 GHz, the corresponding accuracy would be considerably worse at 0.34 g m−3. First, the retrieval of LWC is simulated using aircraft-measured size spectra taken from a profile through marine stratocumulus. Results are then presented from two case studies—one using two cloud radars at Chilbolton in southern United Kingdom, and another using the Cloud Profiling Radar System at the Atmospheric Radiation Measurement site in Oklahoma. The liquid water path from the technique was found to be in good agreement with the values that were obtained from microwave radiometers, with the difference between the two being close to the accuracy of the radiometer retrieval. In the case of well-mixed stratocumulus, the profiles were close to adiabatic.

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HU, ZHENCHENG, and KEIICHI UCHIMURA. "TRINOCULAR STEREO-BASED 3D REPRESENTATION OF DRIVING ENVIRONMENT USING U-V-DISPARITY." International Journal of Information Acquisition 02, no. 02 (June 2005): 137–48. http://dx.doi.org/10.1142/s0219878905000519.

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Laser or millimeter wave radars have shown good performance in measuring relative speed and distance in a highway driving environment. However the accuracy of these systems decreases in an urban traffic environment as more confusion occurs due to factors such as parked vehicles, guardrails, poles and motorcycles. A trinocular stereo-based sensing system provides an effective supplement to radar-based road scene analysis with its much wider field of view and more accurate lateral information. This paper presents an efficient solution using a trinocular stereo based 3D representation method of driving environment which employs the "U-V-disparity" concept. It is used to classify a 3D road scene into relative surface planes and characterize the features of road pavement surfaces, roadside structures and obstacles. Real-time implementation of the trinocular stereo disparity calculation and the "U-V-disparity" classification algorithm is also presented in this paper.

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Suganthi, K., and S. Malarvizhi. "Millimeter wave CMOS minimum noise amplifier for automotive radars in the frequency band (60–66 GHZ)." Cluster Computing 22, S5 (December 26, 2017): 11755–64. http://dx.doi.org/10.1007/s10586-017-1475-2.

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Ajvazyan, H. M., and H. H. Ajvazyan. "Hail embryons detection in clouds using passive and active radars in millimeter and submillimeter wave bands." International Journal of Infrared and Millimeter Waves 14, no. 5 (May 1993): 1155–74. http://dx.doi.org/10.1007/bf02084590.

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Aydell, Taylor B., and Craig B. Clements. "Mobile Ka-Band Polarimetric Doppler Radar Observations of Wildfire Smoke Plumes." Monthly Weather Review 149, no. 5 (May 2021): 1247–64. http://dx.doi.org/10.1175/mwr-d-20-0198.1.

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ABSTRACTRemote sensing techniques have been used to study and track wildfire smoke plume structure and evolution; however, knowledge gaps remain because of the limited availability of observational datasets aimed at understanding fine-scale fire–atmosphere interactions and plume microphysics. Meteorological radars have been used to investigate the evolution of plume rise in time and space, but highly resolved plume observations are limited. In this study, we present a new mobile millimeter-wave (Ka band) Doppler radar system acquired to sample the fine-scale kinematics and microphysical properties of active wildfire smoke plumes from both wildfires and large prescribed fires. Four field deployments were conducted in autumn of 2019 during two wildfires in California and one prescribed burn in Utah. Radar parameters investigated in this study include reflectivity, radial velocity, Doppler spectrum width, differential reflectivity ZDR, and copolarized correlation coefficient ρHV. Observed radar reflectivity ranged between −15 and 20 dBZ in plume, and radial velocity ranged from 0 to 16 m s−1. Dual-polarimetric observations revealed that scattering sources within wildfire plumes are primarily nonspherical and oblate-shaped targets as indicated by ZDR values measuring above 0 and ρHV values below 0.8 within the plume. Doppler spectrum width maxima were located near the updraft core region and were associated with radar reflectivity maxima.

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Qin, Liting, Yunlong Lu, Qingchun You, Yi Wang, Jifu Huang, and Peter Gardner. "Millimeter-Wave Slotted Waveguide Array With Unequal Beamwidths and Low Sidelobe Levels for Vehicle Radars and Communications." IEEE Transactions on Vehicular Technology 67, no. 11 (November 2018): 10574–82. http://dx.doi.org/10.1109/tvt.2018.2866245.

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Wang, Mingyang, Xinbo Chen, Baobao Jin, Pengyuan Lv, Wei Wang, and Yong Shen. "A Novel V2V Cooperative Collision Warning System Using UWB/DR for Intelligent Vehicles." Sensors 21, no. 10 (May 17, 2021): 3485. http://dx.doi.org/10.3390/s21103485.

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The collision warning system (CWS) plays an essential role in vehicle active safety. However, traditional distance-measuring solutions, e.g., millimeter-wave radars, ultrasonic radars, and lidars, fail to reflect vehicles’ relative attitude and motion trends. In this paper, we proposed a vehicle-to-vehicle (V2V) cooperative collision warning system (CCWS) consisting of an ultra-wideband (UWB) relative positioning/directing module and a dead reckoning (DR) module with wheel-speed sensors. Each vehicle has four UWB modules on the body corners and two wheel-speed sensors on the rear wheels in the presented configuration. An over-constrained localization method is proposed to calculate the relative position and orientation with the UWB data more accurately. Vehicle velocities and yaw rates are measured by wheel-speed sensors. An extended Kalman filter (EKF) is applied based on the relative kinematic model to combine the UWB and DR data. Finally, the time to collision (TTC) is estimated based on the predicted vehicle collision position. Furthermore, through UWB signals, vehicles can simultaneously communicate with each other and share information, e.g., velocity, yaw rate, which brings the potential for enhanced real-time performance. Simulation and experimental results show that the proposed method significantly improves the positioning, directing, and velocity estimating accuracy, and the proposed system can efficiently provide collision warning.

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