Direction Finding Research Articles

Pola Komunikasi Interpersonal Siswa SMAN Sidikalang Terhadap Kecanduan Bermain Game Mobile Legend

This research aims to determine the interpersonal communication patterns of SMAN 1 Sidikalang students regarding their addiction to playing Mobile Legends games. This research uses a qualitative descriptive method. This research is a field study. The data in this research comes from primary data obtained directly through direct findings in the research area such as the results of interviews and observations. This research data also comes from secondary data obtained through literature that relates to the research context such as journal articles and books. Data collection techniques in this research used semi-structured interviews and non-participant observation. Data analysis in this research was carried out by reducing, presenting, and then verifying the research data. The results of this research show that the interpersonal communication approach applied by teachers at SMA Negeri 1 Sidikalang is very focused on creating positive relationships with students. They listen attentively, show genuine interest, and avoid unnecessary interruptions. The body language they use supports a positive atmosphere, and simple language creates a comfortable environment. Teachers give praise to increase students' self-confidence and provide criticism wisely. They also demonstrate self-control and emotional maturity, helping students overcome gaming addiction problems. All of these approaches aim to create positive interpersonal relationships and provide important support in student development.

Improving the Direction of Arrival Estimation Using the Parasitic Subspace Generated by Active-Parasitic Antenna (APA) Arrays

The improvement in Direction of Arrival (DOA) estimation when the received signals impinge on Active-Parasitic Antenna (APA) arrays will be studied in this work. An APA array consists of several active antennas; others are parasitic antennas. The responses to the received signals are measured at the loaded terminals of the active element. The terminals of the parasitic element are shorted. The effect of the received signals on the parasites, i.e., the induced short-circuit current, is mutually coupled to the active elements. Eigen decomposition of the covariance matrix of the measurements of the APA array generates a third subspace in addition to the traditional signal and noise subspaces generated by the all-active antenna receiving array. This additional subspace, the parasitic subspace, is accompanied by very small eigenvalues (approaching zero). Hence, a complete orthogonality between this subspace and the column space of the steering matrix of the array can be obtained. As a result, better resolution in estimating the DOA can be achieved. Several simulations in conjunction with the MUSIC algorithm, which have been conducted in this work, depict that the APA array outperforms the all-active antenna array as a direction finder, regardless of the size of the array, the number of active elements, or the number of measurement snapshots. Furthermore, super-resolution DOA estimation can be achieved when a subset of the parasitic subspace is used as if the measurement were noiseless. Also, the APA array contributes to very small RMSE values over a wide range of S/N of the received signals.

Direction Finding With Sparse Subarrays: Design, Algorithms and Analysis

Direction Finding With Sparse Subarrays: Design, Algorithms and Analysis

Increasing the security of radio communications of internal affairs bodies during special operations

the article provides recommendations for employees of internal affairs bodies performing tasks in the context of special operations. The materials contain brief information about the principles of operation of mobile and mobile Swazi means, radio traffic, and direction finding. These recommendations will be useful for understanding the operation of radio equipment from the point of view of secure radio exchange in direction finding conditions and recommendations for increasing the radio communication range.

A Deep Reinforcement Learning-based Shortwave Multistation Autonomous Cooperative Direction Finding and Localization Method

A Deep Reinforcement Learning-based Shortwave Multistation Autonomous Cooperative Direction Finding and Localization Method

Anti-Ambiguity Direction Finding by Harmonics' Amplitudes With Two-Element Time Modulated Array

Anti-Ambiguity Direction Finding by Harmonics' Amplitudes With Two-Element Time Modulated Array

Performance Evaluation Considering Real Usage in Positioning and Direction Finding System Using Radio Signals

Performance Evaluation Considering Real Usage in Positioning and Direction Finding System Using Radio Signals

Linear solution of the passive localization problem with combined single-station direction finding and two-station time difference information

Based on the main station’s direction measurement value and the time difference measurement value of the two stations, two definite solution equations can be listed in the polar coordinate system by directly utilizing the path difference equation and the cosine theorem, and the analytical solution can be obtained by solving the two definite solution equations jointly. Further comparison of the ranging errors shows that the ranging accuracy of the two-station directional and time-difference positioning system is only slightly worse than that of the three-station time-difference positioning system. The new results provide a better basis for the engineering design of two-station hybrid localization.

An Experimental Evaluation Based on Direction Finding Specification for Indoor Localization and Proximity Detection

An Experimental Evaluation Based on Direction Finding Specification for Indoor Localization and Proximity Detection

Single-Channel Direction Finding by Amplitude Correlation With Time Modulated Array

Single-Channel Direction Finding by Amplitude Correlation With Time Modulated Array

Реалізація алгоритму пошуку кореляційного інтерферометричного пеленгатора засобами програмної платформи GNU радіо

In the realm of modern radio equipment development, the integration of Software Defined Radio (SDR) systems, encompassing both software and hardware components, has become widespread. SDR systems, particularly, find applications in the creation of direction finders for radio signal sources. The effectiveness of direction finding and the identification of radio radiation sources largely hinge on the technical specifications of the equipment. For contemporary systems aimed at detecting the location of radio radiation sources, direction finders based on a correlation interferometer prove to be highly suitable. These direction finders excel in performing direction finding for a wide array of radio signals, capable of recognizing broadband modulated signals. They can simultaneously process and identify several signals within a single frequency channel, originating either from a singular source of radio signals (coherent) or from multiple sources (incoherent). SDR technology enables programmable reconfiguration of a radio receiver through software. Such receivers boast a broadband radio frequency component with a significant dynamic range, a high-speed Analog-to-Digital Converter (ADC) path, a robust signal processor, and a specialized digital filtering path. SDR receivers are adaptable to signals of various standards and frequencies, depending on the specific tasks at hand. The GNU RADIO software platform stands out as the most flexible open-source software platform for SDR systems. This article delves into the utilization of the GNU RADIO software platform to implement the search algorithm for the direction finder of the correlation interferometer. The Ettus USRP N210 SDR platform was selected for implementing the direction finder using the correlation interferometer algorithm. This study introduces a two-channel software-controlled model of the direction finder, operating according to the correlation interferometer algorithm. The measurement results for the placement angle of radio signal sources yielded an individual absolute error ranging from 2 to 4 degrees, with an average absolute error of about 3 degrees. These results are quite commendable for such mobile two-channel systems. While systems with four or more channels boast higher accuracy, they tend to have lower economic feasibility.

Результаты анализа грозовой деятельности на территории Республики Северная Осетия – Алания

The paper presents the results of thunderstorm activity study on the territory of the Republic of North Ossetia-Alania, and in particular, in the area of the all-season tourist complex “Mamison”. The analysis of the average annual factors of thunderstorm and lightning activity in the period from 2012 to 2022 in the warm period of time (May-September) according to the LS8000 thunderstorm direction finding system was performed. The estimation of the number of cloud-earth lightning ratios of positive and negative polarity is made, the influence of the orography of the terrain on the magnitude of lightning currents is investigated, the territorial features of the distribution of cloud-earth lightning currents of different polarity are determined. The resulting expression of the linear trend for the number of thunderstorms shows a decrease in thunderstorm activity in recent years in the study area.

Систематические ошибки установки углового положения в матричных имитаторах радиоэлектронной обстановки

Estimates of the error in setting the angular position of the apparent center of radiation by a matrix simulator, which are, in fact, its systematic error, are considered. It is shown that the cause of the error is the replacement of the simulated point emitter by several points. Analytical relations have been obtained that allow calculating the magnitude of the systematic direction fin-ding error based on the characteristics of the matrix simulator and the radiation pattern of the receiving antenna operating with the matrix simulator of the radio engineering system. It is shown that the considered error is completely determined by the nonlinearity of the direction finding characteristic of the antenna. It is established that the error is most significant when simulating the apparent center of radiation outside the matrix. For the area inside the matrix, the dependences of the maximum error values and their angular positions on the shape of the antenna pattern and the specified position of the radiation point are obtained. The relations allowing to estimate errors depending on the ratio of the angular dimensions of the matrix, the width of the antenna radiation pattern and the coefficients of approximation of its radiation pattern are obtained. The reliability of the obtained results is confirmed by comparison with the results obtained by numerical simulation. The results of the work can be used to solve applied problems related to the development of matrix simulators and simulation complexes based on them, as well as to predict their accuracy characteristics.

Software Defined Radio for GNSS Radio Frequency Interference Localization.

The use of radio direction finding techniques in order to identify and reject harmful interference has been a topic of discussion both past and present for signals in the GNSS bands. Advances in commercial off-the-shelf radio hardware have led to the development of new low-cost, compact, phase coherent receiver platforms such as the KrakenSDR from KrakenRF whose testing and characterization will be the primary focus of this paper. Although not specifically designed for GNSSs, the capabilities of this platform are well aligned with the needs of GNSSs. Testing results from both benchtop and in the field will be displayed which verify the KrakenSDR's phase coherence and angle of arrival estimates to array dependent resolution bounds. Additionally, other outputs from the KrakenSDR such as received signal strength indicators and the angle of arrival confidence values show strong connections to angle of arrival estimate quality. Within this work the testing that will be primarily presented is at 900 MHz, with results presented from a government-sponsored event where the Kraken was tested at 1575.42 MHz. Finally, a discussion of calibration of active antenna arrays for angle of arrival is included as the introduction of active antenna elements used in GNSS signal collection can influence angle of arrival estimation.

MRI spectrum of injuries to the thumb metacarpophalangeal joint ulnar collateral ligament with a proposed expanded classification of injuries in American football players.

Injuries to the ulnar collateral ligament of the thumb metacarpophalangeal joint are of both historic and modern interest for athletes and non-athletes alike. The thumb metacarpophalangeal joint requires stability in both flexion and extension utilizing a combination of static and dynamic stabilizers. This article reviews the magnetic resonance imaging categorization of thumb ulnar collateral ligament injuries and proposes two additional injury patterns seen in high-level and professional athletes who play American football. In addition to the direct magnetic resonance imaging findings in collateral ligament tears, secondary findings of rotation and subluxation can be seen at the thumb metacarpophalangeal joint due to the altered physiologic forces on the joint. Internal brace augmentation via suture tape of a traditional ulnar collateral ligament repair is a novel surgical technique that provides protection during initial healing and the ensuing remodeling phase following repair or reconstruction, resulting in a faster return to play.

(p,q)-Post-Widder operators of semi exponential type

We deal here with the (p, q)-variant of the Post-Widder operators of semiexponential type. By using the basic properties of post-quantum properties, we calculate the moments of these operators and obtain some direct findings for such (p, q)-semi-exponential Post-Widder operators.

Four-antenna amplitude direction finder: statistical synthesis and experimental research of signal processing algorithm

The subject of this study is the algorithms for measuring the angular positions of radio emission sources. The goal of this study is to develop an improved algorithm for signal processing in amplitude direction finders that will provide several unambiguous measurement angles at high steepness of the discrimination characteristic by combining measurements of systems with different widths of antenna patterns. The task: to develop an optimal signal processing algorithm for a four-antenna amplitude direction finding system, two antennas of which have a wide radiation pattern and the other two have a narrow one; to test the overall performance of the resulting algorithm by simulating the direction finder; to develop and conduct a study of an experimental model of a four-antenna direction finder, which includes two antennas with wide radiation patterns, two antennas with narrow radiation patterns, radio frequency paths, and a signal processing unit that implements the developed algorithm; to analyze the effectiveness and features of the application of the developed algorithm, and to compare the results of simulation modeling and experimental research. The methods used are statistical methods and optimal solutions for solving problems of statistical synthesis of signal processing algorithms in passive radio systems, computer simulation modeling methods, and experimental research methods. The following results were obtained. The algorithm for signal processing in a four-antenna direction finding system was synthesized using the maximum likelihood method. By simulation modeling, the overall effectiveness of measurement integration in multi-antenna amplitude direction finders was confirmed, and the peculiarities of the synthesized algorithm application were revealed, namely, the need to introduce additional proportionality coefficients into the measurement channels. During the experimental studies of the developed model of the direction finder, the results of the simulation modeling were confirmed. Conclusions. To determine the direction of radiation sources by amplitude direction finders, it is advisable to simultaneously use systems with wide and narrow antenna patterns, the measurements of which are combined by the proposed algorithm. This makes it possible to simultaneously expand the range of unambiguous measurement angles and increase the accuracy of measurements within the equal-signal zone. The disadvantage of using the algorithm is the nonlinear form of the obtained discrimination characteristics and the need to determine additional proportionality coefficients heuristically.

Wideband Machine-Learning-Based Amplitude-Only Direction Finding With Spiral Antennas

Wideband Machine-Learning-Based Amplitude-Only Direction Finding With Spiral Antennas

Performance Bound Optimization for MIMO Radar Direction Finding With MUSIC

Performance Bound Optimization for MIMO Radar Direction Finding With MUSIC

Physical Problems of Direction Finding in the Deep Sea

Physical Problems of Direction Finding in the Deep Sea