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RESEARCH ARTICLE
Superconducting Receiver Technologies Supporting ALMA
Credit: Uzawa et al. 2021, Figure 1

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RESEARCH ARTICLE
Dual‐Polarized FSR with Wide Transmission Band
Credit: Jiao et al. 2021, Figure 17

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RESEARCH ARTICLE
Holographic Calibration of Phased Array Telescopes
Credit: Kiefner et al. 2021, Figure 10

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CALL FOR PAPERS
THz Propagation Characterization, Modeling & Wireless Link design
Credit: Adobe Stock (CC-BY-NC)

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CALL FOR PAPERS
Effect of air-sea coupling electromagnetic propagation
Credit: Denny Alappattu and the CASPER team

Browse Articles

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Issue Information

  •  27 December 2021
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Comparison of Frequency‐Domain Electromagnetic Responses at Different Offsets Based on Exact Calculation of Grounded‐Wire Source

Guoqiang Xue, Nannan Zhou, Dongyang Hou,
  •  27 December 2021

Key Points

  • A point charge element is introduced to decrease or eliminate the error caused by dipole approximation

  • The response expression of the real source, including the source position vector, is derived

  • The electromagnetic characteristics of the entire zone are displayed

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An Efficient and Compact Monopole Antenna Backed With Square Loop EBG Structure for Medical Wireless Body Area Network Applications

Maryam Darabi, Farzad Mohajeri,
  •  27 December 2021

Key Points

  • In this paper, a compact, low-profile, and simple monopole antenna is presented that is operated at the frequency of 2.4 GHz in industrial scientific medical band

  • The monopole antenna is based on the simple rectangular microstrip patch antenna with a rotated T-shaped slot. Furthermore, a 2 × 2 electromagnetic band-gap array is used in this design to act as an isolator between the antenna and human body, which additionally increases the performance of the proposed antenna

  • The final design has an overall size of 0.9λg × 0.9λg × 0.034λg (60 × 60 × 2.3 mm3), where λg is the guided-wavelength with respect to RO4003 substrate at the resonant frequency of 2.4 GHz. This can make the structure a good candidate for wireless body area network applications

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First Observations of the New MEXART's Digital System

J. A. Gonzalez-Esparza, J. C. Mejia-Ambriz, E. Aguilar-Rodriguez, P. Villanueva, E. Andrade, A. Magro, R. Chiello, D. Cutajar, J. Borg, K. Zarb-Adami,
  •  26 December 2021

Key Points

  • Radio telescope dedicated to the study of solar wind properties and space weather effects using the interplanetary scintillation technique

  • The new digital backend has several beamforming configurations, increases the bandwidth, and improves the instrument's sensitivity

  • With the new technical capabilities, the instrument can participate in space weather forecasting and other astrophysical studies

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Performance of Earth Troposphere Calibration Measurements With the Advanced Water Vapor Radiometer for the Juno Gravity Science Investigation

D. R. Buccino, D. S. Kahan, M. Parisi, M. Paik, E. Barbinis, O. Yang, R. S. Park, A. Tanner, S. Bryant, A. Jongeling,
  •  7 December 2021

Key Points

  • This research presents the impacts of Earth troposphere path delay on Juno Gravity Science Doppler frequency measurements

  • The Advanced Water Vapor Radiometer (AWVR) measured short-term and seasonal variations in troposphere path delay in Goldstone, California

  • The AWVR improved Doppler frequency measurements by 46% on average and up to 70% in optimal conditions

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The Geomagnetic Storm Time Response of the Mid Latitude Ionosphere During Solar Cycle 24

Yekoye Asmare Tariku,
  •  6 December 2021

Key Points

  • The effect of the 1 June 2013 and 2015 St. Patrick's Day storms were mostly pronounced in the European sector

  • The effect of the 28 May 2017 storm was mostly pronounced at stations located in the American and Asian sectors

  • The IRI 2016 and IRI-Plas 2017 models Vertical Total Electron Content values generally decrease on most of the hours when the storm on option is applied

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On Use of Low Cost, Compact GNSS Receiver Modules for Ionosphere Monitoring

Sukabya Dan, Atanu Santra, Somnath Mahato, Chaitali Koley, P. Banerjee, Anindya Bose,
  •  6 December 2021

Key Points

  • Navigation satellite signals are used for ionosphere monitoring; geodetic or special purpose navigation receivers are usually used for the purpose. Low-cost, compact, dual-frequency, commercial Global Navigation Satellite System (GNSS) modules have the potential for such applications

  • Signal strength and vertical total electron content (VTEC) values obtained using concurrent GPS data from a geodetic GNSS receiver and a compact GNSS module are compared. The signal strength values from the two types of receivers show a similar variation pattern, and the VTEC values are found to be in extremely close agreement

  • The compact GNSS modules, thus, can be used for ionospheric research with distinct advantages of cost, size and power requirement. Use of the compact, low-cost modules will help in developing a networked, concurrent GNSS-based ionospheric monitoring system over a distributed geographical area

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Automated Detection of Antenna Malfunctions in Large‐N Interferometers: A Case Study With the Hydrogen Epoch of Reionization Array

Dara Storer, Joshua S. Dillon, Daniel C. Jacobs, Miguel F. Morales, Bryna J. Hazelton, Aaron Ewall-Wice, Zara Abdurashidova, James E. Aguirre, Paul Alexander, Zaki S. Ali, Yanga Balfour, Adam P. Beardsley, Gianni Bernardi, Tashalee S. Billings, Judd D. Bowman, Richard F. Bradley, Philip Bull, Jacob Burba, Steven Carey, Chris L. Carilli, Carina Cheng, David R. DeBoer, Eloy de Lera Acedo, Matt Dexter, Scott Dynes, John Ely, Nicolas Fagnoni, Randall Fritz, Steven R. Furlanetto, Kingsley Gale-Sides, Brian Glendenning, Deepthi Gorthi, Bradley Greig, Jasper Grobbelaar, Ziyaad Halday, Jacqueline N. Hewitt, Jack Hickish, Tian Huang, Alec Josaitis, Austin Julius, MacCalvin Kariseb, Nicholas S. Kern, Joshua Kerrigan, Piyanat Kittiwisit, Saul A. Kohn, Matthew Kolopanis, Adam Lanman, Paul La Plante, Adrian Liu, Anita Loots, David MacMahon, Lourence Malan, Cresshim Malgas, Zachary E. Martinot, Andrei Mesinger, Mathakane Molewa, Tshegofalang Mosiane, Steven G. Murray, Abraham R. Neben, Bojan Nikolic, Chuneeta Devi Nunhokee, Aaron R. Parsons, Robert Pascua, Nipanjana Patra, Samantha Pieterse, Jonathan C. Pober, Nima Razavi-Ghods, Daniel Riley, James Robnett, Kathryn Rosie, Mario G. Santos, Peter Sims, Saurabh Singh, Craig Smith, Jianrong Tan, Nithyanandan Thyagarajan, Peter K. G. Williams, Haoxuan Zheng,
  •  6 December 2021

Key Points

  • Monitoring the performance of a many-element system is essential to acquiring science-quality data and requires an automated approach

  • We define metrics based on cross-correlations that assess the health of the whole array and its component subsystems in an automated way

  • We outline metrics based on autocorrelations that identify systematics and provide a generalizable approach to automated antenna flagging

Open access

Using the World Wide Lightning Location Network (WWLLN) to Study Very Low Frequency Transmission in the Earth‐Ionosphere Waveguide: 2. Model Test by Patterns of Detection/Non‐Detection

Abram R. Jacobson, Robert H. Holzworth, James B. Brundell,
  •  2 December 2021

Key Points

  • Suppression of low-latitude Very Low Frequency transmission propagating magnetic west, especially at night

  • Suppression at night applies to nearly the entire westward half-plane, from magnetic South clockwise to magnetic North

  • The magnetic westward suppression at night is readily observable for dip angles in the range −30° to +30°

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Issue Information

  •  23 November 2021
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DOA Estimation of Linear Dipole Array with Known Mutual Coupling based on ESPRIT and MUSIC

Mohamed Bensalem, Ouarda Barkat,
  •  7 January 2022

Key Points

  • DOA estimation

  • known mutual coupling

  • MUSIC, ESPRIT

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Joint Transmitting Subarray Partition and Beamforming for Active Jamming Suppression in Phased‐MIMO Radar

Junsheng Huang, Guangdi Cao,
  •  7 January 2022

Key Points

  • The transmitting array of radar system is partitioned into a certain number of non-overlapped subarrays and the transmit waveforms of all subarrays have the same modulus. And constraining the modulus of each element of the transmit beamformer weight vector of each subarray to 1 can not only ensure that the weighted waveforms of all transmitting antennas still have the same amplitude, but also keep the transmit power of each antenna unchanged, thus efficiently maximizing the power utilization of radar transmitter

  • The transmitting subarray structure and the corresponding transmit beamformer weight vectors are simultaneously optimized by constructing the optimization model of maximizing the SNR of the whole received echoes under certain constraint conditions, so as to effectively reduce the peak sidelobe level of transmit beampattern and improve the radar anti-jamming and target detection performance

  • The adaptive beamforming technique is applied to suppress the jamming signal entering the receiver, so that the transmitting and receiving adaptive degrees of freedom (DOFs) are jointly utilized to enhance the active anti-jamming capability of radar system

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Analysis of HF receiving Antenna SNR and Application

Wenjun Zhu, Lixin Guo, Senior Member, IEEE, Shaolin He,
  •  4 January 2022

Key Points

  • The basis for receiving high frequency antenna design was revealed by synthetically analysis of the antenna and signals to noise ratio

  • A novel high frequency receiving antenna was designed and fabricated

  • A comparison measurement was carried out to verify our proposal and the application

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Diffuse Whistler‐Mode Waves Detected by Kaguya in the Lunar Polar Region

T. Nakagawa, F. Takahashi, H. Shimizu, Y. Saito,
  •  27 December 2021

Key Points

  • Diffuse emission of whistler-mode waves from 1 Hz to 16 Hz is found over the polar regions of the moon in the solar wind

  • Right-hand polarized waves propagate parallel to the background magnetic field without a significant Doppler shift

  • The waves are thought to be generated by the ions reflected by the moon and propagate along field lines convected by the solar wind

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The Distribution Characteristics of GPS Cycle Slip Over the China Mainland and Adjacent Region During the Declining Solar Activity (2015–2018) Period of Solar Cycle 24

Wei Geng, Wengeng Huang, Guoqi Liu, Siqing Liu, Binxian Luo, Yanhong Chen,
  •  23 April 2021

Key Points

  • The temporal and spatial characteristics of cycle slips are analyzed using the GPS data detected from almost 260 observations in the China sector during the period of the year 2015–2018

  • The variations of cycle slip are dependent on the local time, seasons, solar activity, and latitudes

  • The feature of cycle slip occurrence is related to the solar activity and distribution of ionospheric scintillation above a certain intensity level over the China region

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Global Positioning System Observations of Ionospheric Total Electron Content Variations During the 15th January 2010 and 21st June 2020 Solar Eclipse

A. Silwal, S. P. Gautam, P. Poudel, M. Karki, B. Adhikari, N. P. Chapagain, R. K. Mishra, B. D. Ghimire, Y. Migoya-Orue,
  •  23 April 2021

Key Points

  • Solar eclipse is a phenomenon that has a direct influence on the Earth's ionosphere

  • The measure of the decrease in vertical value of total electron content during the eclipse hours are correlated with the partial and complete obscuration of solar radiation

  • The scale of the reduction is closely associated with the eclipse magnitude

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High‐Precision Carrier Tracking Algorithm for Extremely Weak and High‐Dynamic Signals

Tao Deng, Maoli Ma, Qinghui Liu, Yajun Wu,
  •  23 April 2021

Key Points

  • A novel low pass denoising method is proposed

  • A improved PLL with excellent performance is achieved

  • The proposed method is suitable for high-precision carrier tracking in deep space exploration, especially for high-dynamic and weak signals

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Superconducting Receiver Technologies Supporting ALMA and Future Prospects

Y. Uzawa, Y. Fujii, T. Kojima, M. Kroug, W. Shan, S. Ezaki, A. Miyachi, H. Kiuchi, A. Gonzalez,
  •  18 April 2021

Key Points

  • We developed highly sensitive terahertz receivers for the Atacama Large Millimeter/submillimeter Array

  • Seventy-three receivers with NbTiN-based superconducting mixers were successfully produced at the National Astronomical Observatory of Japan

  • Next-generation receivers to enhance the capabilities of the current telescope are being developed

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A Detection Performance Analysis of Sanya Incoherent Scatter Radar Tristatic System

Ning Zhang, Mingyuan Li, Biqiang Zhao, Lingqi Zeng, Xinan Yue, Honglian Hao, Junyi Wang, Feng Ding, Baiqi Ning, Weixing Wan,
  •  16 April 2021

Key Points

  • Multistatic phased array Incoherent scatter radars (ISR) equation for soft target is derived

  • The detection performances of phased array monostatic and bistatic ISR are analyzed for pulse width, height, beam width and scattering volume

  • Optimal tilt and rotation angles of receiving array are suggested for Sanya incoherent scatter radar (SYISR) tristatic system

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Data Assimilation Retrieval of Electron Density Profiles From Ionosonde Virtual Height Data

Victoriya V. Forsythe, Irfan Azeem, Ryan Blay, Geoff Crowley, Roman A. Makarevich, Wanli Wu,
  •  16 April 2021

Key Points

  • New method to retrieve the bottom side electron density from virtual height data is developed based on Kalman filter equations

  • The derivation of the Jacobian for virtual height data assimilation is presented

  • The assimilative inversion of virtual height data outperforms the polynomial analysis inversion algorithm

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Satellite radar interferometry: Two‐dimensional phase unwrapping

Richard M. Goldstein, Howard A. Zebker, Charles L. Werner,
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A global mapping technique for GPS‐derived ionospheric total electron content measurements

A. J. Mannucci, B. D. Wilson, D. N. Yuan, C. H. Ho, U. J. Lindqwister, T. F. Runge,

Vegetation modeled as a water cloud

E. P. W. Attema, Fawwaz T. Ulaby,

Geodesy by radio interferometry: Effects of atmospheric modeling errors on estimates of baseline length

J. L. Davis, T. A. Herring, I. I. Shapiro, A. E. E. Rogers, G. Elgered,
  • Radio Science
  •  1593-1607
  •  November-December 1985
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Singular value decomposition methods for wave propagation analysis

O. Santolík, M. Parrot, F. Lefeuvre,

Estimation of tropospheric delay for microwaves from surface weather data

J. Askne, H. Nordius,
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International Reference Ionosphere 2000

Dieter Bilitza,
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Statistics of total electron content depletions observed over the South American continent for the year 2008

G. K. Seemala, C. E. Valladares,

Key Points

  • First time regional plots of TEC depletions
  • New numerical algorithm developed to automatically detect TEC depletions
  • Day-to-day variability of TEC depletions in a regional basis

AIM: Adaptive integral method for solving large‐scale electromagnetic scattering and radiation problems

E. Bleszynski, M. Bleszynski, T. Jaroszewicz,
  • Radio Science
  •  1225-1251
  •  1 September 1996

An improved equation for the radio refractive index of air

Gordon D. Thayer,
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An Indoor Path Loss Prediction Model Using Wall Correction Factors for Wireless Local Area Network and 5G Indoor Networks

H. A. Obeidat, R. Asif, N. T. Ali, Y. A. Dama, O. A. Obeidat, S. M. R. Jones, W. S. Shuaieb, M. A. Al-Sadoon, K. W. Hameed, A. A. Alabdullah, R. A. Abd-Alhameed,

Key Points

  • A modified effective wall loss model (EWLM) for indoor environment is presented
  • Real-time measurements and simulations for various indoor path loss models are used
  • Several frequency spectrum band were considered for evaluation purposes

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Long‐term observations of Schumann resonances at Modra Observatory

A. Ondrášková, P. Kostecký, S. Ševčík, L. Rosenberg,
Open access

Measurement of Ionospheric Total Electron Content Using Single‐Frequency Geostationary Satellite Observations

C. Cooper, C. N. Mitchell, C. J. Wright, D. R. Jackson, B. A. Witvliet,

Key Points

  • The derivation of total electron content using single-frequency terrestrial GPS receivers and geostationary satellites is demonstrated
  • The demonstrated technique is validated by correlation analysis
  • The correlations between TEC time series for pairs of receivers and between receivers and an ionosonde over a year show good agreement

Plain Language Summary

The ionized upper portion of the atmosphere is known as the ionosphere. The ionosphere interferes with signals traveling between satellites and the ground and can cause errors in satellite navigation, surveillance, and communication systems. The impact of these errors can be reduced if we are able to measure the total electron content (TEC), which can be simply thought of as the total number of electrons in a straight line between a satellite and the ground. We have developed a technique that allows us to measure TEC using receivers measuring single-frequency signals from geostationary satellites. This is useful because it will increase the number of measurements available and because using geostationary satellites makes the measurements relatively easy to interpret. To test the technique we use a correlation analysis to compare measurements made by the single-frequency receivers. We also correlate technique measurements with independent TEC observations made by an ionosonde. All correlation results showed good agreement, suggesting consistency for the technique, and that the technique is reliable. The demonstrated technique has the potential to become a routine method to derive TEC, which will help to map the ionosphere in real time.

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Accurate measurements of the dielectric constant of seawater at L band

Roger Lang, Yiwen Zhou, Cuneyt Utku, David Le Vine,

Key Points

  • Dielectric measurements of seawater are made with a microwave cavity at 1.413 GHz
  • Measurements are made as a function of temperature and salinity for values found in open ocean
  • Accuracy is better than 0.3 for both real and imaginary parts of the dielectric constant

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Software‐Defined Radio Decoding of DCF77: Time and Frequency Dissemination with a Sound Card

Jean-Michel Friedt, Clément Eustache, Émile Carry, Enrico Rubiola,

Key Points

  • DCF77 signals are used for time of flight measurement using Software-defined radio processing
  • A 10 μs resolution time measurement and sub-ppm frequency resolution with a sound card are demonstrated
  • Ionospheric delay characterization for educational purposes and long-term instigation with low-cost equipment has been developed

Plain Language Summary

Software-defined radio aims at reducing to its minimum the hardware setup needed to process radio frequency signals and relies on software processing for demodulation: here we demonstrate the precise measurement of an atomic clock-locked emitter, propagating at very low frequency, using only a general purpose computer sound card. Thanks to the high accuracy of the time of flight accessible through an improved modulation schemes, such physical properties as ionosphere altitude and ground wave versus air wave are detected. The frequency of the atomic clock is compared with the sound card local oscillator frequency, demonstrating the temperature dependence of the latter, readily measured in this experiment.

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Radio wave propagation through vegetation: Factors influencing signal attenuation

Nick Savage, David Ndzi, Andrew Seville, Enric Vilar, John Austin,
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Calculating the absorption of HF radio waves in the ionosphere

K. A. Zawdie, D. P. Drob, D. E. Siskind, C. Coker,

Key Points

  • Either the Appleton-Hartree or Sen Wyller dispersion relation can be used to calculate absorption
  • It is necessary to utilize the correct collision frequency specification for each dispersion relation
  • Geophysical variations of collision frequency should be included in absorption calculations

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Fresnel Reflection and Transmission Coefficients for Temporally Dispersive Attenuative Media

Kurt E. Oughstun, Christopher L. Palombini,

Key Points

  • General expressions for Fresnel reflection and transmission coefficients for homogeneous and inhomogeneous plane waves are derived for TE- and TM polarized plane waves in complex media with loss
  • The critical angle for total internal reflection remains unchanged when material loss is included; the polarizing angle (for a TM polarized plane wave is changed otherwise, a pseudo Brewster's angle occurs at which the magnitude of the TM) polarization reflection coefficient is a minimum
  • Total reflection at grazing incidence on the optically denser medium does not occur when both media exhibit loss; total reflection does not occur at critical incidence when both media exhibit loss.

Plain Language Summary

Amplitude reflection and transmission coefficients for a time-harmonic electromagnetic plane wave incident upon a plane interface separating two different lossy media are developed.

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Digital transmission techniques for a long haul HF link: DSSS versus OFDM

P. Bergadà, R. M. Alsina-Pagès, J. L. Pijoan, M. Salvador, J. R. Regué, D. Badia, S. Graells,

Key Points

  • Advanced modulation techniques applied to HF communications
  • Spread spectrum and OFDM modulations for ionospheric transmissions

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Singular value decomposition methods for wave propagation analysis

O. Santolík, M. Parrot, F. Lefeuvre,

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