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1
Chen, Xiang, Yuheng Chen, Shuai Cao, Lei Zhang, Xu Zhang e Xun Chen. "Acoustic Indoor Localization System Integrating TDMA+FDMA Transmission Scheme and Positioning Correction Technique". Sensors 19, n. 10 (22 maggio 2019): 2353. http://dx.doi.org/10.3390/s19102353.
Testo completoAbstract (sommario):
This paper presents a novel audio indoor localization system. In the proposed system, four speakers placed at known positions transmit chirp signals according to the time-division multiple access (TDMA) plus frequency-division multiple access (FDMA) transmission scheme. A smartphone receives the signal via a built-in microphone and calculates the time differences of arrival (TDOAs). Using TDOA measurements, the position is estimated by the shrinking-circle method. In particular, to reduce the positioning error in moving conditions, a TDOA correction method based on Doppler shifts is proposed. The performance of the proposed system was evaluated in real-world experiments using a 10.971 m × 5.684 m positioning area. The results of the static-target positioning experiment showed that the TDMA+FDMA transmission scheme has more advantages in improving the update rate of the positioning system than the TDMA-only transmission scheme. The results of the moving-target positioning experiment under three different speeds demonstrated that the positioning errors were reduced by about 10 cm when the Doppler-shift-based TDOA correction method was adopted. This research provides a possible framework for the realization of a TDOA-chirp-based acoustic indoor positioning system with high positioning accuracy and update rate.
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Luo, Ji-An, Zhi-Wen Tan e Dong-Liang Peng. "A novel bearing-assisted TDOA-GROA approach for passive source localization". International Journal of Intelligent Computing and Cybernetics 11, n. 1 (12 marzo 2018): 2–19. http://dx.doi.org/10.1108/ijicc-11-2016-0056.
Testo completoAbstract (sommario):
Purpose The passive source localization (PSL) problem using angles of arrival (AOA), time differences of arrival (TDOA) or gain ratios of arrival (GROA) is generally nonlinear and nontrival. In this research, the purpose of this paper is to design an accurate hybrid source localization approach to solve the PSL problem. The inspiration is drawn from the fact that the bearings, TDOAs and GROAs are complementary in terms of their geometry properties. Design/methodology/approach The maximum-likelihood (ML) method is reexamined by using hybrid measurements. Being assisted by the bearings, a new hybrid weighted least-squares (WLS) method is then proposed by jointly utilizing the bearing, TDOA and GROA measurements. Findings Theoretical performance analysis illustrates that the mean-square error of the ML or WLS method can attain the Cramér-Rao lower bound for Gaussian noise over small error region. However, the WLS method has much lower computational complexity than the ML algorithm. Compared with the AOA-only, TDOA-only, AOA-TDOA, TDOA-GROA methods, the localization accuracy can be greatly improved by combining the AOAs, TDOAs and GROAs, especially for some specific geometries. Originality/value A novel bearing-assisted TDOA-GROA method is proposed for source localization, and a new hybrid WLS estimator is presented inspired from the fact that the bearings, TDOAs and GROAs are complementary in terms of their geometry properties.
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Ouyang, Xinxin, Shanfeng Yao e Qun Wan. "A Coherent Integrated TDOA Estimation Method for Target and Reference Signals". Electronics 11, n. 16 (22 agosto 2022): 2632. http://dx.doi.org/10.3390/electronics11162632.
Testo completoAbstract (sommario):
The performance of a time difference of arrival (TDOA) localization system is severely affected by time synchronization errors, and making use of reference signals is a common solution for the problem. The traditional method has two steps, first to measure the TDOAs of the target signal and reference signal separately, and next, to compensate the estimated target TDOA with the difference of the estimated reference TDOA and the true reference TDOA. Since the performance of the TDOA estimation is mainly decided by the frequency information, a coherent integration TDOA estimation method for the target signal and reference signal is proposed in this paper, based on cross correlation phase difference compensation, with use of the signals’ frequencies. First, as per the traditional method, the separated cross correlation functions of the target signal and reference signal were obtained by cross correlation, and the target TDOA and reference TDOA of the separate method were estimated. Next, the cross correlation phase was analyzed for each signal. Then the coherent integration cross correlation was obtained with phase compensation, from which the estimation of the target TDOA and reference TDOA could simultaneously be achieved. We performed simulation comparisons with the two methods, and showed that the proposed algorithm provided better performance.
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Wada, Atsushi, e Shingo Yoshizawa. "Transmission of Depth Data by Pulse Position Modulation for Underwater Acoustic Positioning Systems". International Journal of Circuits, Systems and Signal Processing 16 (30 maggio 2022): 999–1006. http://dx.doi.org/10.46300/9106.2022.16.122.
Testo completoAbstract (sommario):
This paper presents a three dimensional localization method for underwater acoustic positioning systems. In typical ultra-short baseline (USBL) acoustic positioning systems, the three dimensional position is localized by using multiple time difference of arrivals (TDOAs). Since the TDOA accuracy is less than the other sensor data, we focus on a localization method with the minimum number of TDOA. We propose a method of transmitting depth data by pulse position modulation (PPM), where the target position is localized by a single TDOA, a distance, and a depth. The proposed method shows a higher positional accuracy than the conventional method with two TDOAs. The effectiveness of the proposed method has been demonstrated in the evaluation of simulation and experiment.
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Deng, Wang, Zheng, Fu, Yin, Tang e Yang. "A Closed-Form Localization Algorithm and GDOP Analysis for Multiple TDOAs and Single TOA Based Hybrid Positioning". Applied Sciences 9, n. 22 (16 novembre 2019): 4935. http://dx.doi.org/10.3390/app9224935.
Testo completoAbstract (sommario):
Cellular communication systems support mobile phones positioning function for Enhanced-911 (E-911) location requirements, but the positioning accuracy is poor. The fifth-generation (5G) cellular communication system can use indoor distribution systems to provide accurate multiple time-difference-of-arrival (TDOA) and single time-of-arrival (TOA) measurements, which could significantly improve the indoor positioning ability. Unlike iterative localization algorithms for TDOA or TOA, the existing closed-form algorithms, such as the Chan-Ho algorithm, do not have convergence problems, but can only estimate position based on one kind of measurement. This paper proposes a closed-form localization algorithm for multiple TDOAs and single TOA measurements. The proposed algorithm estimates the final position result using three-step weighted least squares (WLSs). The first WLS provides an initial position for the last two steps. Then the algorithm uses two WLSs to estimate position based on heteroscedastic TDOA and TOA measurements. In addition, the geometric dilution of precision (GDOP) of the proposed hybrid TDOA and TOA positioning has been derived. The analysis of GDOP shows that the proposed hybrid positioning has lower GDOP than TDOA-only positioning, which means the proposed hybrid positioning has a higher accuracy limitation than TDOA-only positioning. The simulation shows that the proposed localization algorithm could have better performance than closed-form TDOA-only positioning methods, and the positioning accuracy could approximate Cramer-Rao lower bound (CRLB) when the TDOA measurement errors are small.
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IBRAHIM, NUR. "Pendeteksian Lokasi Sumber Noise (Partial Discharge) secara Tiga Dimensi menggunakan Antenna Array". ELKOMIKA: Jurnal Teknik Energi Elektrik, Teknik Telekomunikasi, & Teknik Elektronika 3, n. 2 (1 luglio 2015): 106. http://dx.doi.org/10.26760/elkomika.v3i2.106.
Testo completoAbstract (sommario):
ABSTRAKPada penelitian ini akan dilakukan simulasi teknik pendeteksian lokasi sumber noise berupa partial discharge (PD) pada peralatan tegangan tinggi, dengan menggunakan susunan antena yang terdiri dari empat buah antena monopole sebagai sensor untuk mendeteksi gelombang elektromagnetik (EM) yang dipancarkan dari partial discharge (PD). Algoritma yang digunakan mengacu kepada time difference of arrival (TDOA) dari sinyal yang diterima antar antena (dengan menjadikan salah satu antena sebagai antena referensi). Metode yang digunakan untuk menentukan TDOA adalah metode Akaike Information Criterion, metode Energy Criterion, metode Gabor Centroid, metode threshold detection, metode peak detection, dan metode cross-correlation. Sistem pendeteksian lokasi sumber noise ini menggunakan konfigurasi susunan antena membentuk Y. Jarak antar antena diatur sejauh 2 meter dan 4 meter. Berdasarkan hasil pengamatan dan analisis, konfigurasi susunan antena membentuk Y memiliki tingkat akurasi 97.67%. Metode yang paling akurat untuk menentukan TDOA adalah metode cross-correlation.Kata kunci: PD, TDOA, susunan antena.ABSTRACTThis paper presents a simulation of locating noise source (Partial Discharge) on high-voltage apparatuses, by using antenna array that consisted of four monopole antennas as sensor to record the electromagnetic waves (EM) emitted from Partial Discharge (PD). The detection algorithm is based on the time difference of arrival (TDOA) of the signals received between antennas (by using one of four antennas as reference antenna). The methods to determine TDOAs are Akaike Information Criterion method, Energy Criterion method, Gabor Centroid method, threshold detection method, peak detection method, and/or cross-correlation method. These system use Y-shaped array configuration. The adjusted distance between antennas are 2 meter and 4 meter. From the observation and analysis results, Y-shaped array antenna configuration has accuracy 97.76%. The best method to get TDOA is the cross-correlation method.Keywords: PD, TDOA, antenna array.
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Yuk, Simun, e Youngho Cho. "A Time-Based Dynamic Operation Model for Webpage Steganography Methods". Electronics 9, n. 12 (10 dicembre 2020): 2113. http://dx.doi.org/10.3390/electronics9122113.
Testo completoAbstract (sommario):
The webpage steganography technique has been used for a covert communication method for various purposes in which a sender embeds a secret message into a plain webpage file like an HTML file by using various steganography methods. With human eyes, it is very difficult to distinguish between the original webpage (cover webpage) and the modified webpage with the secret data (stego webpage) because both are displayed alike in a web browser. In this approach, when two communicating entities want to share a secret message, a sender uploads a stego webpage to a web server or modifies an existing webpage in the web server by using a webpage steganography method, and then a receiver accesses the stego webpage to download and extract the embedded secret data from it. Meanwhile, according to our extensive survey, we observed that most webpage steganography methods focused on proposing or improving steganography algorithms but did not well address how to operate a stego webpage as time passes. However, if a stego webpage is used in a static way such that the stego webpage does not change and is constantly exposed to web clients until the sender removes it, such a static operation approach will limit or badly affect the hiding capacity and undetectability of a webpage steganography method. By this motivation, in this paper, we proposed a time-based dynamic operation model (TDOM) that improves the performance of existing webpage steganography methods in terms of hiding capacity and undetectability by dynamically replacing the stego webpage with other stego webpages or the original webpage. In addition, we designed two time-based dynamic operation algorithms (TDOA-C and TDOA-U), which improve the hiding capacity of existing methods and TDOA-U for improving the undetectability of existing methods, respectively. To validate our model and show the performance of our proposed algorithms, we conducted extensive comparative experiments and numerical analysis by implementing two webpage steganography methods with our TDOM (CCL with TDOA-C and COA with TDOA-C) and tested them in the web environment. According to our experiments and analysis, our proposed algorithms could significantly improve the hiding capacity and undetectability of two existing webpage steganography methods.
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Liu, Yan, e Fucheng Guo. "Fast TDOA and FDOA Estimation for Coherent Pulse Signals". International Journal of Antennas and Propagation 2022 (20 settembre 2022): 1–9. http://dx.doi.org/10.1155/2022/5390970.
Testo completoAbstract (sommario):
Time difference of arrival (TDOA) and frequency difference of arrival (FDOA) have been widely used for localizing temporally continuous signals passively. Temporal sparsity of pulse signals makes their TDOA and FDOA estimation processes much different, and computational complexity is a major concern in this area. This paper addresses the problem of fast TDOA and FDOA estimation of pulse signals and focuses mainly on narrowband coherent pulses. By decoupling the effects of TDOA and FDOA in the cost function of localization approximately, we propose a fast coarse TDOA and FDOA estimation method. The estimates are then refined with the cross-ambiguity function (CAF) algorithm within a small TDOA and FDOA neighborhood. In the simulations, the proposed method is demonstrated to have satisfying TDOA and FDOA estimation precisions, and it exceeds existing counterparts largely in computational efficiency.
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Permana, Andriyan, Agfianto Eko Putra e Catur Atmaji. "Analisis Perkiraan TDOA menggunakan Algoritma LMS Adaptif pada Pelacakan Paus Lodan". IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) 5, n. 1 (1 maggio 2015): 11. http://dx.doi.org/10.22146/ijeis.7149.
Testo completoAbstract (sommario):
AbstrakPenelitian mengenai perkiraan TDOA dalam pelacakan paus lodan telah dilakukan[1] yang menggunakan Teager-Kaiser operator dalam peningkatan akurasi perkiraan nilai TDOA untuk pelacakan paus lodan menggunakan algoritma LMS adaptif. Namun demikian, belum dilakukan penelitian lebih lanjut mengenai faktor konvergensi (μ) yang tepat (cepat dan akurat) pada perkiraan TDOA menggunakan algoritma LMS adaptif untuk pelacakan paus lodan. Akan dilakukan analisis perkiraan nilai TDOA menggunakan algoritma LMS adaptif pada pelacakan posisi paus lodan dengan variasi nilai μ. Pada penelitian ini, sebagai acuan untuk menentukan nilai μ yang tepat, digunakan hasil pelacakan paus pada penelitian [2].Perkiraan TDOA menggunakan algoritma LMS Adaptif pertama kali dipublikasikan oleh Benesty [3]. Pendekatan yang dilakukan berdasarkan pada perkiraan tanggap impulsional dari sumber ke penerima. Pada algoritma LMS adaptif dilakukan pembaruan nilai koefisien dengan μ sebagai langkah adaptasi. Nilai TDOA diperoleh dari selisih jarak dua tanggap impulsional.Dari hasil penelitian diperoleh hasil bahwa perubahan nilai μ mempengaruhi kecepatan perkiraan TDOA menggunakan algoritma LMS adaptif. Akan tetapi, nilai μ yang tidak tepat mengakibatkan hasil pelacakan paus tidak akurat. Dari penelitian ini diperoleh nilai μ terbaik untuk perkiraan TDOA menggunakan algoritma LMS adaptif pada pelacakan posisi paus lodan adalah 0.01. Kata kunci— perkiraan TDOA, LMS adaptif, faktor konvergensi, pelacakan paus lodan AbstractResearch on TDOA estimation in sperm whale tracking has been done [1] that uses the Teager - Kaiser operator in improving accuracy the TDOA estimation using adaptive LMS algorithm on sperm whale tracking. However, further researches on the right convergence factor (μ) (fast and accurate) in TDOA estimation using adaptive LMS algorithms for sperm whale tracking have not been performed. Will be analyzed the TDOA estimation using adaptive LMS algorithm in sperm whale tracking with the variation of μ. As a reference to determine the right value of μ, the results of sperm whale tracking[2] is used.TDOA estimation using Adaptive LMS algorithm was first published by Benesty [3]. The approach taken is based on estimation of the impulse responses from source to receivers. In the adaptive LMS algorithm function updates the coefficient with μ as adaptation step. TDOA values obtained from the difference between the two impulse responses.From the results, values changing of μ affect the speed of TDOA estimation using the LMS adaptive algorithm. However, the wrong value of μ is lead to inaccurate sperm whale tracking results. The best value of μ for TDOA estimation using the LMS adaptive algorithm for sperm whale tracking is 0.01. Keywords— TDOA estimation, adaptive LMS, convergence factor, sperm whale tracking
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Yaro, Abdulmalik Shehu, Ahmad Zuri Sha'ameri e Sa’id Musa Yarima. "Direct and Indirect TDOA Estimation based Multilateration System Position Estimation Accuracy Comparison". ELEKTRIKA- Journal of Electrical Engineering 20, n. 1 (30 aprile 2021): 54–64. http://dx.doi.org/10.11113/elektrika.v20n1.226.
Testo completoAbstract (sommario):
Multilateration (MLAT) system estimate aircraft position from its electromagnetic emission using time difference of arrival (TDOA) estimated at ground receiving station (GRS)s with a lateration algorithm. The position estimation (PE) accuracy of the MLAT system depends on several factors one of which is the TDOA estimation approach. In this paper, the PE performance of a minimum configuration 3-dimensional (3-D) MLAT system based on the direct and indirect approaches to TDOA estimation is presented. The analysis is carried out using Monte Carlo simulation with the transmitter and receiver parameters based on an actual system used in the civil aviation. Simulation results show that within 150 km radius, the direct TDOA based MLAT system performs better than the indirect TDOA based MLAT system. Beyond 150 km radius, the indirect TDOA based MLAT system has the least PE error compared the direct TDOA based MLAT system. Further comparison of the MLAT system based on the two TDOA estimation approaches with other surveillance systems shows that the direct TDOA based MLAT system has the least PE error within 150 km radius while long-range aircraft PE beyond 150 km, automatic surveillance dependent broadcast (ADS-B) outperformed the MLAT system as it has the least PE error
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Jang, Junsu, Florian Meyer, Eric Snyder, Sean Wiggins, Simone Baumann-Pickering e John Hildebrand. "Bayesian detection and tracking of odontocetes in 3D from their echolocation clicks". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A176. http://dx.doi.org/10.1121/10.0018572.
Testo completoAbstract (sommario):
To study behaviors of marine mammals in a nonintrusive manner, their bio-acoustical signals can be recorded by volumetric hydrophone arrays that provide time difference of arrival (TDOA) measurements for localization and tracking. Multi-target tracking (MTT) in 3-D using TDOA measurements from multiple sensors, however, must cope with non-linear measurement models and high-dimensional states. False alarms, missed detections and unknown data associations impose further challenges, often requiring human operators to annotate the data manually. We propose a data processing chain that automatically detects and tracks odontocetes from their echolocation clicks. The echolocation clicks are detected with a generalized cross-correlation that whitens the instrument noise. Two stages of tracking are performed using a tracking framework based on factor graphs and the sum-product algorithm (SPA). The odontocetes are first tracked in the TDOA domain to remove false alarms and then in the 3-D domain, fusing the tracked TDOAs across all sensors. To efficiently handle the considered non-linear and high-dimensional MTT scenario, particle flow is embedded in the SPA. According to simulation results, the proposed tracking method outperforms the existing approach using manual data annotation. Tracking of Cuvier’s beaked whales (Ziphius cavirostris), whose echolocation clicks are recorded by two volumetric hydrophone arrays, is demonstrated.
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Hubáček, Petr, Jiří Veselý e Jana Olivová. "The Complete Analytical Solution of the TDOA Localization Method". Defence Science Journal 72, n. 2 (11 maggio 2022): 227–35. http://dx.doi.org/10.14429/dsj.72.16933.
Testo completoAbstract (sommario):
This article is focused on the analytical solution of a TDOA (Time Difference of Arrival) localization method, including analysis of accuracy and unambiguity of a target position estimation in 2D space. The method is processed under two conditions - sufficiently determined localization system and an overdetermined localization system. It is assumed that the TDOA localization system operates in a LOS (Line of Sight) situation and several time-synchronized sensors are placed arbitrarily across the area. The main contribution of the article is the complete description of the TDOA localization method in analytical form only. It means, this paper shows a geometric representation and an analytical solution of the TDOA localization technique model. In addition, analyses of unambiguity and solvability of the method algorithm are presented, together with accuracy analysis of this TDOA technique in analytical form. Finally, the description of this TDOA method is extended to an overdetermined TDOA system. This makes it possible to determine and subsequently optimize its computational complexity, for example increase its computational speed. It seems that such a description of the TDOA localization technique creates a simple and effective tool for technological implementation of this method into military localization systems.
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Yu, Ziyuan, Jin Liu, Chao Pan, Lvqian Guo, Zhiwei Kang e Xin Ma. "Solar TDOA measurement and integrated navigation for formation flying". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, n. 12 (febbraio 2019): 4635–45. http://dx.doi.org/10.1177/0954410019827148.
Testo completoAbstract (sommario):
To improve the positioning accuracy of autonomous celestial navigation systems when flying in formation, we exploit the fact that the sole light source in the solar system is the Sun to directly provide positioning information for relative navigation. We term this solar Time Difference of Arrival (TDOA) navigation for formation flying. Solar light has the potential to provide a solar Time of Arrival (TOA) because of its unstable intensity. However, the solar TOA cannot be used for navigation because it has no baseline. To solve this problem, we took the difference between the solar TOAs of two spacecraft (the solar TDOA) as the basis for navigational measurement. The solar TDOA represents the relative distance between two spacecraft in a radial direction. However, whilst the solar TDOA is insensitive to solar direction errors, a free-standing solar TDOA navigation system is not observable. We therefore combined the solar TDOA with the Mars direction and inter-satellite link navigation system, to form an integrated solar TDOA/Mars direction/inter-satellite link navigation method for formation flying. Simulation results indicate that solar TDOA-based integrated navigation for formation flying can provide highly accurate navigation information, especially under relative conditions.
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Liu, Chang, Fengshan Bai e Chunsheng Wu. "A Joint Positioning Algorithm of TDOA and TOF Based on Ultra-wideband". Journal of Physics: Conference Series 2031, n. 1 (1 settembre 2021): 012039. http://dx.doi.org/10.1088/1742-6596/2031/1/012039.
Testo completoAbstract (sommario):
Abstract Ultra-wideband (UWB) positioning is a mainstream positioning technology in recent years, and the main positioning algorithms used in UWB based positioning systems are TDOA and TOA. Aiming at the problem of unstable positioning accuracy of TDOA algorithm in traditional UWB positioning system, this paper proposes a joint positioning algorithm of TDOA and TOF based on UWB. The algorithm needs only one time of TOF ranging and combined with the TDOA algorithm, the distances between all base stations and a single tag in the positioning area can be obtained. Compared with the single TDOA algorithm, the algorithm has stable measurement accuracy and can achieve the same positioning accuracy whether the tag is inside or outside the triangle formed by the base station. The simulation results show that the average positioning error of the joint positioning algorithm of TDOA and TOF is less than 10 cm. The algorithm is effective and reliable, and meets the positioning requirements.
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Zhou, Junjie, LiangJie Shen e Zhenlong Sun. "A New Method of D-TDOA Time Measurement Based on RTT". MATEC Web of Conferences 207 (2018): 03018. http://dx.doi.org/10.1051/matecconf/201820703018.
Testo completoAbstract (sommario):
In this paper, a novel difference-time difference of arrival (D-TDOA) time measurement method based on round-trip transmission (RTT) is proposed. The accuracy of time measurement is critical for high accuracy positioning, yet the traditional time difference of arrival (TDOA) time measurement method cannot deal well with the problem of time synchronization error, such as the initial time offset and transmission cumulate time error caused by clock frequency offset and drift. We formulate a D-TDOA time measurement mechanism to overcome the shortcoming of the traditional TDOA method in eliminating the influence of clock error. It is proved that the D-TDOA method can effectively eliminate the influence of initial time offset by analyzing the simulation data, which can also reduce the cumulate time error remarkably. The simulation results demonstrate that the D-TDOA method can significantly enhance the accuracy of time measurement in the circumstance that the AP clock synchronization is not required seriously.
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Xin, Jihao, Xuyang Ge, Yuan Zhang, Xingdong Liang, Hang Li, Linghao Wu, Jiashuo Wei e Xiangxi Bu. "High-Precision Time Difference of Arrival Estimation Method Based on Phase Measurement". Remote Sensing 16, n. 7 (29 marzo 2024): 1197. http://dx.doi.org/10.3390/rs16071197.
Testo completoAbstract (sommario):
In unmanned aerial vehicle (UAV)-based time difference of arrival (TDOA) positioning technique, baselines are limited due to communication constraints. In this case, the accuracy is highly sensitive to the TDOA measurements’ error. This article primarily addresses the problem of short-baseline high-precision time synchronization and TDOA measurement. We conducted a detailed analysis of error models in TDOA systems, considering both the time and phase measurement. We utilize the frequency division wireless phase synchronization technique in TDOA systems. Building upon this synchronization scheme, we propose a novel time delay estimation method that relies on phase measurements based on the integer least squares method. The performance of this method is demonstrated through Monte Carlo simulations and outdoor experiments. The standard deviations of synchronization and TDOA measurements in experiments are 1.12 ps and 1.66 ps, respectively. Furthermore, the circular error probable (CEP) accuracy is improved from 0.33%R to 0.02%R, offering support for the practical application of distributed short-baseline high-precision passive location techniques.
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Jiang, Yi, Qing Hu e Dongkai Yang. "Analysis of Positioning Error for Two-Dimensional Location System". Mathematical Problems in Engineering 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/163958.
Testo completoAbstract (sommario):
This paper investigates the positioning error using different positioning techniques for two-dimensional location system. Based on the measurement models of TOA with/without the time synchronization and TDOA techniques, the performance comparison analysis between TOA with/without the time synchronization and TDOA is presented respectively. The performance of TOA with the time synchronization and TDOA is influenced by the specific distribution of the reference nodes. Hence, it is hard to determine which one is better. The performance of TDOA is always superior to TOA without the time synchronization using the same reference nodes. These conclusions are finally illustrated by the simulation results presented in two scenarios.
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Feng, Miao, Zhaoning Gu e Shiliang Fang. "A Multiple Target Data Association Method for TDOA Passive Localization". INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, n. 6 (1 febbraio 2023): 1828–33. http://dx.doi.org/10.3397/in_2022_0258.
Testo completoAbstract (sommario):
In order to solve the multiple target data association problem in underwater acoustic passive localization system, a new algorithm focus on data association in Time Difference of Arriva l(TDOA) is studied. Firstly, the zero-sum condition is used to select TDOA measurements according to the continuous measurement values within a certain period of time. Then, the selected TDOA measurements are associated with the multiple targets and the correct correlation probability is measured by the correlation degree. The algorithm is used in sea trial. Processing results show that the method proposed in this paper can effectively solve the TDOA measurement association problem, and can locate multiple targets at the same time.
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Aernouts, Michiel, Noori BniLam, Rafael Berkvens e Maarten Weyn. "TDAoA: A combination of TDoA and AoA localization with LoRaWAN". Internet of Things 11 (settembre 2020): 100236. http://dx.doi.org/10.1016/j.iot.2020.100236.
Testo completo
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Li, Jinzhou, Shouye Lv, Liujie Lv, Sheng Wu, Yang Liu, Jing Nie, Ying Jin e Chenglin Wang. "Joint TDOA, FDOA and PDOA Localization Approaches and Performance Analysis". Remote Sensing 15, n. 4 (7 febbraio 2023): 915. http://dx.doi.org/10.3390/rs15040915.
Testo completoAbstract (sommario):
Multi-station joint localization has important practical significance. In this paper, phase difference of arrival (PDOA) information is introduced into the joint time difference of arrival (TDOA) and frequency difference of arrival (FDOA) localization method to improve the target localization accuracy. First, the Cramer–Rao lower bound (CRLB) of the joint TDOA, FDOA and PDOA localization approach with multi-station precise phase synchronization is derived. Then, the CRLB of the joint TDOA, FDOA and differential PDOA (dPDOA) localization method for the case of phase asynchronization between observation stations is also presented. Furthermore, the authors analyze the influence of the phase wrapping problem on localization accuracy and propose solutions to solve the phase wrapping problem based on cost functions of grid search. Finally, iterative localization algorithms based on maximum likelihood (ML) are proposed for both TDOA/FDOA/PDOA and TDOA/FDOA/dPDOA scenarios, respectively. Simulation results demonstrate the localization performance of the proposed approaches.
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Liu, Qi, Rongyi Hu e Shan Liu. "A Wireless Location System in LTE Networks". Mobile Information Systems 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/6160489.
Testo completoAbstract (sommario):
Personal location technologies are becoming important with the rapid development of Mobile Internet services. In traditional cellular networks, the key problems of user location technologies are high-precision synchronization among different base stations, inflexible processing resources, and low accuracy positioning, especially for indoor environment. In this paper, a new LTE location system in Centralized Radio Access Network (C-RAN) is proposed, which makes channel and location measurement more available, allocation of baseband processing resources more flexible, and location service capability opening. The location system contains more than two antenna clusters, and each of them gets time-difference-of-arrival (TDOA) of sounding reference signals (SRSs) from different antennas. Then, based on data provided by location measurement units (LMUs), the location information server calculates TDOAs and derives the users’ position. Furthermore, a new location algorithm is raised which can achieve distributed antennas collaboration and centralized location computing. And an improved optimized algorithm with the best TDOA selection is proposed. Finally, simulations are given out to verify the efficiency of the proposed algorithm in this LTE location system.
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Li, Fengquan, Zhuling Sun, Mingyuan Liu, Shanfeng Yuan, Lei Wei, Chunfa Sun, Huimin Lyu, Kexin Zhu e Guoying Tang. "A New Hybrid Algorithm to Image Lightning Channels Combining the Time Difference of Arrival Technique and Electromagnetic Time Reversal Technique". Remote Sensing 13, n. 22 (18 novembre 2021): 4658. http://dx.doi.org/10.3390/rs13224658.
Testo completoAbstract (sommario):
Very-high-frequency (VHF) electromagnetic signals have been well used to image lightning channels with high temporal and spatial resolution due to their capability to penetrate clouds. A lightning broadband VHF interferometer with three VHF antennas configured in a scalene-triangle shape has been installed in Lhasa since 2019, to detect the lightning VHF signals. Using the signals from the VHF interferometer, a new hybrid algorithm, called the TDOA-EMTR technique, combining the time difference of arrival (TDOA) and the electromagnetic time reversal (EMTR) technique is introduced to image the two-dimensional lightning channels. The TDOA technique is firstly applied to calculate the initial solutions for the whole lightning flash. According to the results by the TDOA method, the domain used for the EMTR technique is predetermined, and then the EMTR technique is operated to obtain the final positioning result. Unlike the original EMTR technique, the low-power frequency points for each time window are removed based on the FFT spectrum. Metrics used to filter noise events are adjusted. Detailed imaging results of a negative cloud-to-ground (CG) lightning flash and an intra-cloud (IC) lightning flash by the TDOA method and the TDOA-EMTR are presented. Compared with the original EMTR method, the positioning efficiency can be improved by more than a factor of 3 to 4, depending on the scope of the pre-determined domain. Results show that the new algorithm can obtain much weaker radiation sources and simultaneously occurring sources, compared with the TDOA method.
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Stefański, Jacek. "ASYNCHRONICZNA METODA TDOA". PRZEGLĄD TELEKOMUNIKACYJNY - WIADOMOŚCI TELEKOMUNIKACYJNE 1, n. 4 (5 aprile 2015): 180–83. http://dx.doi.org/10.15199/59.2015.4.44.
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Dogancay, Kutluyil, e Hatem Hmam. "3D TDOA Emitter Localization Using Conic Approximation". Sensors 23, n. 14 (9 luglio 2023): 6254. http://dx.doi.org/10.3390/s23146254.
Testo completoAbstract (sommario):
This paper develops a new time difference of arrival (TDOA) emitter localization algorithm in the 3D space, employing conic approximations of hyperboloids associated with TDOA measurements. TDOA measurements are first converted to 1D angle of arrival (1D-AOA) measurements that define TDOA cones centred about axes connecting the corresponding TDOA sensor pairs. Then, the emitter location is calculated from the triangulation of 1D-AOAs, which is formulated as a system of nonlinear equations and solved by a low-complexity two-stage estimation algorithm composed of an iterative weighted least squares (IWLS) estimator and a Taylor series estimator aimed at refining the IWLS estimate. Important conclusions are reached about the optimality of sensor–emitter and sensor array geometries. The approximate efficiency of the IWLS estimator is also established under mild conditions. The new two-stage estimator is shown to be capable of outperforming the maximum likelihood estimator while performing very close to the Cramer Rao lower bound in poor sensor–emitter geometries and large noise by way of numerical simulations.
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Ma, Shuang, Zheng Liu e Wen Li Jiang. "Pulse Sorting Algorithm Using TDOA in Multiple Sensors System". Advanced Materials Research 571 (settembre 2012): 665–70. http://dx.doi.org/10.4028/www.scientific.net/amr.571.665.
Testo completoAbstract (sommario):
Time difference of arrival (TDOA) can be used for pulse sorting. To solve the problem of deceptive TDOA clusters caused by high pulse repetitive frequency (PRF) emitters and the problem of less pulse accumulation caused by ultra-low PRF emitters, a recursive extended histogram (REH) algorithm is proposed. TDOA data are formed into an extended histogram structure, which is processed recursively to detect and sort out the pulses of each emitter. Simulation results show that the method is applicable and effective.
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Jafari, Ahmadreza, Luca Petrillo, Julien Sarrazin, David Lautru, Philippe De Doncker e Aziz Benlarbi-Delai. "TDOA estimation method using 60 GHz OFDM spectrum". International Journal of Microwave and Wireless Technologies 7, n. 1 (19 marzo 2014): 31–35. http://dx.doi.org/10.1017/s1759078714000324.
Testo completoAbstract (sommario):
In the field of high data rate wireless communications, localization issues play a key role in achieving energy-efficient communication and geographic routing. time-difference of arrival (TDOA)-based localization methods present numerous advantages. In this paper, a new method of TDOA estimation is proposed. With this method, unlike conventional TDOA measurements, it is possible to perform communication and localization at the same time by using a multi-input single-output system. By transmitting ultra-wide-band orthogonal frequency-division multiplexing signals using spatial diversity, it is possible to extract TDOA from interference patterns in spectral domain. In addition, increasing the precision of localization is also studied using a multi-band approach. This whole study is made within the framework of the WiGig alliance specifications; however, it is compatible with other standards.
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Ma, Guoning, Zhijiang Huang, Ming Wang, Zhengyu Ji, Xianglu Li, Bo Shen e Jie Tian. "Performance Analysis and Sensor-Target Geometry Optimization for TOA and TDOA-Based Hybrid Source Localization Method". Applied Sciences 12, n. 24 (17 dicembre 2022): 12977. http://dx.doi.org/10.3390/app122412977.
Testo completoAbstract (sommario):
Currently, the performance analysis of positioning algorithms and optimization of ground station deployment schemes are predominantly based on pure TOA or TDOA measurement information, and the relevant theoretical analysis is primarily the geometric analysis of optimal station deployment for fixed point targets, with few placement ranges and amount of station constraints. In practice, however, there are typically several measurements from TOA and TDOA stations, with a focus on positioning precision within a certain region or line trajectory, as well as the necessity for constraints on the ground station placement range. This paper proposes an efficient method for hybrid source localization using TOA and TDOA measurement information, establishes a mathematical model for hybrid source localization based on TOA and TDOA measurement information, derives and simulates the Gauss–Newton iterative localization algorithm with the least squares criterion, and performs a theoretical analysis of the least squares error and CRLB boundary to improve the accuracy of target localization in the aforementioned scenarios. Taking the average CRLB value of target line trajectory positioning error as the objective function, the ground station placement scheme of TOA- and TDOA-receiving sensors is optimized by utilizing a Genetic Algorithm with strong global optimization capability under the constraints of station placement range and station quantities, and a station placement geometry with better performance than typical station placement is obtained. Meanwhile, we summarize the general placement principles for TOA and TDOA hybrid source localization of target line trajectories.
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Kim, Jonghoek. "TDOA-Based Target Tracking Filter While Reducing NLOS Errors in Cluttered Environments". Sensors 23, n. 9 (8 maggio 2023): 4566. http://dx.doi.org/10.3390/s23094566.
Testo completoAbstract (sommario):
We consider tracking a moving target in a wireless communication system that is based on the radio signal. Considering a bounded workspace with many unknown obstacles, we handle tracking a non-cooperative transmitter using multiple signal receivers. Here, a non-cooperative transmitter is a transmitter whose signal emission time is not known in advance. We consider a time difference of arrival (TDOA) location problem, which locates the transmitter by processing the signal measurement time at multiple receivers. In tracking a non-cooperative transmitter, non-line-of-sight (NLOS) errors occur if obstacles block the LOS line connecting the receiver and the moving transmitter. Our article addresses how to track a moving transmitter while decreasing the NLOS error in TDOA-only measurements. We propose an algorithm to localize a transmitter while decreasing the NLOS error in TDOA measurements. For tracking a moving transmitter in real time, we integrate the proposed localization algorithm and the interacting multiple model Kalman filter (IMM KF). As far as we know, our article is novel in tracking a moving transmitter based on TDOA-only measurements in an unknown mixed LOS/NLOS workspace. We show that the proposed filter considerably decreases the NLOS errors in TDOA-only measurements while running fast. Therefore, the proposed tracking scheme is suitable for tracking a moving transmitter in real time. Through MATLAB simulations, we show that the proposed filter outperforms other state-of-the-art TDOA filters, considering both time efficiency and tracking accuracy.
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Li, Xiaolong, Yi Xing e Zhenkai Zhang. "A Hybrid AOA and TDOA-Based Localization Method Using Only Two Stations". International Journal of Antennas and Propagation 2021 (27 settembre 2021): 1–8. http://dx.doi.org/10.1155/2021/5512395.
Testo completoAbstract (sommario):
Target localization plays an important role in the application of radar, sonar, and wireless sensor networks. In order to improve the localization performance using only two stations, a hybrid localization method based on angle of arrival (AOA) and time difference of arrival (TDOA) measurements is proposed in this paper. Firstly, the optimization model for localization based on AOA and TDOA are built, respectively, in the sensor network. Secondly,the majorization-minimization (MM) method is employed to create surrogate functions for solving the multiple objective optimization problem. Next, the hybrid localization problem is solved by the projected gradient decent (PGD) method. Finally, the Cramer–Rao lower bound (CRLB) for the joint AOA and TDOA method is derived for the comparison. Simulations proved that the proposed method has improved localization performance using AOA and TDOA measurements from only two base stations.
30
Feng, Fei, Ya Sheng Zhang, Bo Ou e Geng Chen. "The Research about Interference Location Based on Different Times of TDOA with Two Satellites". Applied Mechanics and Materials 713-715 (gennaio 2015): 1132–36. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.1132.
Testo completoAbstract (sommario):
In this paper, we propose an interference location method based on different times of TDOA (the time difference of arrival) which only used two satellites (the main satellite and its adjacent satellite). Firstly, the model of interference location is built based on two different TDOA data and one spheroid model of earth. Subsequently, a series of practical data of communication satellites are calculated with this model and the trust-region method, aiming to test the validity of the proposed model. Furthermore, comparing with some other methods, such as some researchers based on TDOA and FDOA (the frequency difference of arrival) or TDOA method using three satellites, the result of our method is much more accurate (the interference could be located to 20 km successfully) and more available. Numerical simulations are made to verify the capability and validity of the proposed method.
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Mar, Jeich, Shin Ru Wu, Yu Ting Wang e Kuei Chou Tsai. "A Three-Dimensional Position System Using Digital TDE Receiver and Cylindrical Array Antenna". Applied Mechanics and Materials 284-287 (gennaio 2013): 2603–8. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.2603.
Testo completoAbstract (sommario):
Based on the digital time delay estimation (TDE) and Gauss-Newton Interpolation algorithms, the circular error probability (CEP) of the proposed four-station position system using time difference of arrival (TDOA) over Rayleigh fading channel was studied by numerical computation in three-dimension space. The hybrid three-station TDOA and direction of arrival (DOA) position system was used to improve the reliability of four-station TDOA position system. Simulations indicate that the accuracy of the proposed position system is significantly decreased by reducing one measuring station and providing one direction of arrival (DOA) measurement.
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XU, WANG, e ZI SHU HE. "A Weighed Least Square TDOA Location Algorithm for TDMA Multi-target". International Journal of Wireless and Microwave Technologies 1, n. 2 (15 aprile 2011): 16–25. http://dx.doi.org/10.5815/ijwmt.2011.02.03.
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Legkostup, V. V. "Method of spatial cross-coupling elimination of control system channels for object guidance using two TDoA measurements". Proceedings of the National Academy of Sciences of Belarus, Physical-Technical Series 67, n. 4 (2 gennaio 2023): 409–20. http://dx.doi.org/10.29235/1561-8358-2022-67-4-409-420.
Testo completoAbstract (sommario):
The problem of object guidance to the target point using two time difference of arrival (TDoA) measurements obtained from three navigation positions is considered. A general equation that describes a kinematic trajectory of the object along the line of intersection of two object position hyperboloids corresponding to the two TDoA measurements is obtained. It has been found out that the kinematic trajectory of the object lies in a plane perpendicular to the plane of three navigation positions. This kinematic trajectory can be described by the conic equation in the general case, and in the range of position parameters used in practice this equation yields a hyperbola. A method of elimination of object spatial cross-coupled link between control system channels, consisting in a special projection of accelerations of the object during their transformation from the measuring coordinate system to the wind coordinate system is described. This made it possible to implement object control in TDoA navigation system with three navigation positions only using two identical expressions of the kinematic link obtained for a planar case without full spatial equation for kinematic link of the object’s motion and TDoA information. A computer simulation of the object guidance to a target point in space using two TDoA measurements was performed to check the accordance of the acceleration design expressions, which produced a positive results of viewed method. The approach described in the article makes it possible to implement object guidance using TDoA navigation system if available only three of four required navigation positions.
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Ren, Wen-juan, Dong-hui Hu e Chi-biao Ding. "Multi-TDOA Location Algorithm for Three Satellites TDOA Passive Location System". JOURNAL OF RADARS 1, n. 3 (26 novembre 2012): 262–69. http://dx.doi.org/10.3724/sp.j.1300.2012.20050.
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Huo, Lihuan, Rulong Bai, Man Jiang, Bing Chen, Jianfeng Chen, Penghui Huang e Guisheng Liao. "A Tri-Satellite Interference Source Localization Method for Eliminating Mirrored Location". Sensors 21, n. 13 (30 giugno 2021): 4483. http://dx.doi.org/10.3390/s21134483.
Testo completoAbstract (sommario):
With the increase in satellite communication interference, the tri-satellite time difference of arrival (TDOA) localization technique, which is an effective method to determine the location of the interference using sensors or antennas, has been developed rapidly. The location of the interference source is determined through the intersection of the TDOA lines of position (LOP). However, when the two TDOA LOP have two mirrored intersection points, it is theoretically difficult to determine the real location. Aiming at this problem, a method for eliminating mirrored location based on multiple moment TDOA is proposed in this paper. First, the TDOA results are measured at multiple moments using the cross-ambiguity function (CAF), and the localization equation set is established based on the World Geodetic System (WGS)-84 earth ellipsoid model. Then, the initial location result can be obtained by solving the equation set through the Newton iteration method. Finally, the high-precision location result after eliminating the mirrored location is obtained after the single moment localization based on the initial location. Simulation experiments and real measured data processing results verify the effectiveness of the proposed method. It still has good robustness under the condition of large measurement errors and deviations from the prior initial values.
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Ouyang, Xinxin, Shanfeng Yao e Qun Wan. "Multiple Signal TDOA/FDOA Joint Estimation with Coherent Integration". Electronics 12, n. 9 (8 maggio 2023): 2151. http://dx.doi.org/10.3390/electronics12092151.
Testo completoAbstract (sommario):
Passive localization relies significantly on the estimation of the Time Difference of Arrival (TDOA) and Frequency Difference of Arrival (FDOA) to accurately determine the location of a target. The precision of TDOA and FDOA estimation is affected by signal parameters of time and frequency distribution. In case of multiple signals arising at different frequency bands and intercepted simultaneously by spatially separate sensors covering a wide frequency band, the traditional method is first to separate the signals from the mixed wideband signal through digital down conversion (DDC), which brings multiple narrowband signals, and then the estimation of TDOA and FDOA of each narrowband signal can be performed using cross ambiguity function (CAF). The paper introduces a novel approach for estimating TDOA and FDOA of multiple signals simultaneously, which employs a coherent integration method. First, the cross ambiguity function for each signal is realized with the narrowband signal as the same as the traditional method. Next, the phase relation of each CAF is analyzed, then the joint CAF can be obtained with phase compensation, from which multiple signal TDOA and FDOA estimations will be implemented simultaneously. Numerical simulations are performed to compare the two methods, and the results demonstrate the superiority of the proposed algorithm.
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Yoshizawa, Shingo. "Underwater Acoustic Localization Based on IR-GCC-PHAT in Reverberant Environments". International Journal of Circuits, Systems and Signal Processing 15 (12 marzo 2021): 164–71. http://dx.doi.org/10.46300/9106.2021.15.18.
Testo completoAbstract (sommario):
This paper presents a method of underwater acoustic localization in reverberant environments. Time difference of arrival (TDOA) measurement algorithm is a key technology for estimating direction of arrival (DOA) of an underwater sound source. In strong multipath interference, the pseudo-peaks in a correlation function disturb the detection of a correct time position and lead to a large TDOA measurement error. The proposed algorithm computes a time difference by taking cross-correlation of two impulse responses and improves robustness to multipath interference. The comparison of TDOA algorithms is done by evaluating the position accuracy of underwater sound source in both simulation and experiment.
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Xie, Wupeng, Guanghong Liu, Xiaoxiao Xiang, Kang Xing e Xiaojuan Zhang. "Time Difference of Arrival Estimation of Stationary Targets Utilizing Deep Neural Network". Journal of Physics: Conference Series 2414, n. 1 (1 dicembre 2022): 012021. http://dx.doi.org/10.1088/1742-6596/2414/1/012021.
Testo completoAbstract (sommario):
Abstract Time difference of arrival (TDOA) is widely used in the field of passive location because of its flexible base station deployment and simple principle. However, when solving the solution of stationary targets position, the traditional method, such as the two-stage weighted least squares (TSWLS) algorithm, is easily affected by noise, and cannot achieve good localization results in practical situations. To solve this problem, we propose a deep neural network (DNN) for TDOA estimation of stationary targets. First, a large number of simulation samples are generated according to the TDOA model. Each sample contains the time difference from each secondary base station to the main base station, the error of time difference, and the real three-dimensional (3-D) coordinates of the targets. Next, a suitable DNN architecture is designed to solve the solution of the stationary target position. The simulation results prove that the method proposed herein outperforms TSWLS for multiple base stations based on the TDOA model.
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Wang, Yuqi, Guang-Cai Sun, Yong Wang, Jun Yang, Zijing Zhang e Mengdao Xing. "A Multi-Pulse Cross Ambiguity Function for the Wideband TDOA and FDOA to Locate an Emitter Passively". Remote Sensing 14, n. 15 (24 luglio 2022): 3545. http://dx.doi.org/10.3390/rs14153545.
Testo completoAbstract (sommario):
The time difference of arrival (TDOA) and frequency difference of arrival (FDOA) between two receivers are widely used to locate an emitter. Algorithms based on cross ambiguity functions can simultaneously estimate the TDOA and FDOA accurately. However, the algorithms, including the joint processing of received data, require transferring a large volume of data to a central computing unit. It can be a heavy load for the data link, especially for a wideband signal obtained at a high sampling rate. Thus, we proposed a multi-pulse cross ambiguity function (MPCAF) to compress the data before transmitting and then estimate the TDOA and FDOA with the compressed data. The MPCAF consists of two components. First, the raw data are compressed with a proposed two-dimensional compression function. Two methods to construct a reference pulse used in the two-dimensional compression function are considered: a raw data-based method constructs the pulse directly from the received signal, and a signal parameter-based method constructs it through the parameters of the received signal. Second, a wideband cross-correlation function is studied to refine the TDOA and FDOA estimates with the compressed data. The simulation and Cramer–Rao lower bound (CRLB) analyses show that the proposed method dramatically reduces the data transmission load but estimate the TDOA and FDOA well. The hardware-in-the-loop simulation confirms the method’s effectiveness.
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Woźniak, Szymon, e Konrad Kowalczyk. "Reverberation-Robust Self-Calibration and Synchronization of Distributed Microphone Arrays by Mitigating Heteroscedasticity and Outlier Occurrence in TDoA Measurements". Sensors 24, n. 1 (25 dicembre 2023): 114. http://dx.doi.org/10.3390/s24010114.
Testo completoAbstract (sommario):
The network of distributed microphone arrays is usually established in an ad hoc manner; hence, network parameters such as the mutual positioning and rotation of the arrays, positions of sources, and synchronization of their recording onset times are initially unknown. In this article, we consider the problem of passively jointly self-calibrating and synchronizing distributed arrays in reverberant rooms. We use a typical two-step approach where, initially, the relative geometry of the network is estimated using Direction of Arrival (DoA) measurements. Subsequently, the absolute scale and synchronization parameters are estimated using Time Difference of Arrival (TDoA) measurements. This article presents methods to improve the robustness and accuracy of estimation of the absolute geometric scaling and synchronization parameters in reverberant conditions, in which TDoA measurements do not follow a normal distribution; furthermore, outliers often occur. To remedy these issues, we propose a Weighted Least Squares (WLS) estimator and schema for weighting the TDoA measurements to increase the estimation accuracy from heteroscedastic TDoA measurements. In addition, we propose an iterative reweighing algorithm with a binary weight to detect and reject TDoA outliers, which exploits the residuals of the parametric model in the least absolute value minimization. A numerical evaluation shows significant improvements in the proposed method over the state of the art in terms of the relative scaling error and mean absolute value of the synchronization parameters.
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Shehu Yaro, Abdulmalik. "Aircraft Position Estimation Comparison of Multilateration System Lateration Algorithms with Different Reference Selection Techniques". ELEKTRIKA- Journal of Electrical Engineering 18, n. 1 (24 aprile 2019): 16–21. http://dx.doi.org/10.11113/elektrika.v18n1.133.
Testo completoAbstract (sommario):
The lateration algorithm is used by the multilateration (MLAT) system to estimation the position of an aircraft using a time difference of arrival (TDOA) measurement vector generated from its transponder emissions detected at spatially deployed ground station (GS)s. The accuracy at which the aircraft position is determined by the lateration algorithm depends on several factors two of which are the choice and number of reference GSs used in generating the TDOA measurement vector. This paper compares the aircraft PE accuracy of a lateration algorithm using TDOA measurement vector generated using a single and double GS reference selection techniques which are respectively based on signal-to-noise (SNR) and condition number computations. The PE accuracy comparison is carried out at some selected aircraft positions with the GSs in a square configuration distribution. Monte Carlo (MC) simulation result shows that the PE error obtained by the lateration algorithm using TDOA measurement vector generated with the double GS reference selection technique is on the average 20% less than that obtained using the single GS reference selection technique.
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Mao, Yi, Yongwen Zhu, Zhili Tang e Zhijie Chen. "A Novel Airspace Planning Algorithm for Cooperative Target Localization". Electronics 11, n. 18 (17 settembre 2022): 2950. http://dx.doi.org/10.3390/electronics11182950.
Testo completoAbstract (sommario):
With the development of modern electromagnetic stealth technology and ARM, traditional active radar detection cannot accomplish its detection mission, limited by its ability. Relying on such superior advantages such as imperceptibility, anti-electromagnetic interference and electromagnetic stealth, passive transducers are playing an indispensable and significant role in situation awareness. While, in addition to different passive transducer localization modes and solutions of target’s location, the reasonable planning and optimal layout of passive transducers’ location are other major factors affecting the precision of localization. Planning an optimal airspace for passive transducers is the key problem to improve the monitoring efficiency. This paper proposes the optimal layout algorithm for the cooperative platform in the space based on the geometrical relationship of cooperative localization. For example, the principle of direction location in traditional methods is simple: only two passive sensors can work, but the location accuracy of long-distance targets is low. At the same time, TDOA (Time Difference Of Arrival) location has high accuracy and good stability, but it needs at least three passive sensors to work together, which requires the most resources. In this paper, a platform optimization layout algorithm based on direction and TDOA hybrid positioning is proposed. Compared with direction positioning, it improves the long-distance positioning accuracy, reduces the number of sensors required for TDOA positioning, and reduces the resource occupancy rate. However, the TDOA positioning data mixed with direction positioning data inevitably leads to the decline of overall accuracy. In order to solve these difficulties, the weighted least square method is used to optimize the accuracy. The simulation shows that, within the designated target airspace, the optimal action airspace can be generated automatically based on the platforms’ cooperation mode. If there is no resource limitation, the airspace planning based on TDOA positioning has the highest accuracy for the target. However, in practical application, considering the resource limitation, the hybrid positioning of direction and TDOA can also meet the requirements of high accuracy and high stability. The average error is reduced by more than 45% compared with direction positioning, and the airspace occupancy is reduced by more than 30% compared with TDOA positioning. The goal of minimizing the scope of platform airspace planning is realized.
43
Song, Wei Guo, e Yi De Li. "One Algorithm for TDOA/AOA Combined Position". Advanced Materials Research 562-564 (agosto 2012): 2139–44. http://dx.doi.org/10.4028/www.scientific.net/amr.562-564.2139.
Testo completoAbstract (sommario):
Aiming at the position problem of emitter on the ground, this paper puts forward one TDOA/AOA combined position algorithm. In this algorithm, one sensor can be placed on one fixed platform on the ground to measure the azimuth and pitch angle between this sensor and the emitter. Another sensor can be placed on one moving platform, and the different TDOA (Time Difference Of Arrival) can be measured at different time, then the LS (Least Square) algorithm can be reached to solve the evaluated value of the emitter’s position. The simulation results show that this algorithm can increase the position precision effectively, especially the more TDOA measurements are used, the more position precision is.
44
Wen, Xiping, e Jinxia Wang. "TDOA Location Accuracy Experiment". Journal of Physics: Conference Series 1237 (giugno 2019): 032031. http://dx.doi.org/10.1088/1742-6596/1237/3/032031.
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Zhu, Yanping, Bowen Deng, Aimin Jiang, Xiaofeng Liu, Yibin Tang e Xiao Yao. "ADMM-Based TDOA Estimation". IEEE Communications Letters 22, n. 7 (luglio 2018): 1406–9. http://dx.doi.org/10.1109/lcomm.2018.2833546.
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Gotthans, Jakub, Tomas Gotthans e David Novak. "Improving TDOA Radar Performance in Jammed Areas through Neural Network-Based Signal Processing". Sensors 23, n. 6 (7 marzo 2023): 2889. http://dx.doi.org/10.3390/s23062889.
Testo completoAbstract (sommario):
This paper presents a method for estimating the position of a target under jammed conditions using the Time Difference of Arrival (TDOA) method. The algorithm utilizes a deep neural network to overcome the challenges posed by the jammed conditions. The simulations and results indicate that the presented method is more accurate and efficient than the traditional TDOA methods.
47
Wang, Xiaoran, Xiandong Liu, Tian He, Junfei Tai e Yingchun Shan. "A Novel Joint Localization Method for Acoustic Emission Source Based on Time Difference of Arrival and Beamforming". Applied Sciences 10, n. 22 (13 novembre 2020): 8045. http://dx.doi.org/10.3390/app10228045.
Testo completoAbstract (sommario):
Time difference of arrival (TDOA) method and beamforming method are often individually utilized in the localization of acoustic emission source of a plate. Based on the performances of the two methods, a novel joint localization method for acoustic emission source is proposed in this paper. Firstly, the performances of TDOA method and beamforming method are studied based on the simulation signals. Then, aiming at the advantages and disadvantages of these two methods, a joint localization method is proposed. Finally, the performances of joint localization method are verified by simulation and experiment. Both simulation and experimental results show that the accuracy of the joint localization method is improved, and the calculation amount is greatly reduced in comparison to the TDOA method and the beamforming method.
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Kabir, Homayun, Jeevan Kanesan, Ahmed Wasif Reza e Harikrishnan Ramiah. "A Mathematical Algorithm of Locomotive Source Localization Based on Hyperbolic Technique". International Journal of Distributed Sensor Networks 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/384180.
Testo completoAbstract (sommario):
Recent trend shows that sensors situated on an axis in two-dimensional scenario measuring the time difference of arrival (TDOA) and frequency difference of arrival (FDOA) of the emitting signal from a moving source can estimate the emitting signal’s position and velocity from the intersection point of hyperbola, which derives from TDOA and FDOA. However, estimating the location of an emitter based on hyperbolic measurements is a highly nonlinear problem with inconsistent data, which are created due to the measurement noise, the deviation between assumption model and actual field of the velocity, and so forth. In addition, the coefficient matrix of TDOA and FDOA equations set is singular in the linear sensor array network (LSAN). In this paper, a noniterative and simpler method is proposed to locate the instantaneous position of the moving source in LSAN by estimating the position and velocity based on TDOA and FDOA which does not have the convergence problem. In addition, the method avoids the singularity problem of LSAN by introducing the nuisance variables. The proposed method achieved the theoretical lower bound for near to far field with same and different velocity and different baseline of sensors in low to moderate noise.
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Liu, Weili, Jing Zhang, Wei Wei, Tao Qin, Yuanchen Fan, Fei Long e Jing Yang. "A Hybrid Bald Eagle Search Algorithm for Time Difference of Arrival Localization". Applied Sciences 12, n. 10 (21 maggio 2022): 5221. http://dx.doi.org/10.3390/app12105221.
Testo completoAbstract (sommario):
The technology of wireless sensor networks (WSNs) is developing rapidly, and it has been applied in diverse fields, such as medicine, environmental control, climate prediction, monitoring, etc. Location is one of the critical fields in WSNs. Time difference of arrival (TDOA) has been widely used to locate targets because it has a simple model, and it is easy to implement. Aiming at the problems of large deviation and low accuracy of the nonlinear equation solution for TDOA, many metaheuristic algorithms have been proposed to address the problems. By analyzing the available literature, it can be seen that the swarm intelligence metaheuristic has achieved remarkable results in this domain. The aim of this paper is to achieve further improvements in solving the localization problem by TDOA. To achieve this goal, we proposed a hybrid bald eagle search (HBES) algorithm, which can improve the performance of the bald eagle search (BES) algorithm by using strategies such as chaotic mapping, Lévy flight, and opposition-based learning. To evaluate the performance of HBES, we compared HBES with particle swarm algorithm, butterfly optimization algorithm, COOT algorithm, Grey Wolf algorithm, and sine cosine algorithm based on 23 test functions. The comparison results show that the proposed algorithm has better search performance than other reputable metaheuristic algorithms. Additionally, the HBES algorithm was used to solve the TDOA location problem by simulating the deployment of different quantities of base stations in a noise situation. The results show that the proposed method can obtain more consistent and precise locations of unknown target nodes in the TDOA localization than that of others.
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Deng, Zhong Liang, e Xiao Guan Wang. "The Kalman Positioning Algorithm Based on TDOA/AOA". Advanced Materials Research 739 (agosto 2013): 602–7. http://dx.doi.org/10.4028/www.scientific.net/amr.739.602.
Testo completoAbstract (sommario):
TDOA is a common used positioning method. Its advantage is to overcome the disadvantage that positioning time reference is strictly required in TOA method, and the measurement method is relatively simple. AOA needs only two base stations to realise positioning in theory, but the positioning accuracy is lower. TDOA/AOA hybrid positioning algorithm can certainly overcome this limitation to realize high precision positioning. Kalman filter is an optimum regression data processing algorithm. It is applicated widely in various optimal filtering and optimal control problems. For most of the problems, it is optimal, the most efficient and even the most useful. In this article Kalman filter algorithm is utilized to estimate the value of TDOA and AOA, which is used for position calculating to improve the accuracy of positioning.