scholarly journals Source Geolocation in Urban Environments Using Multipath Fingerprinting

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Ram M. Narayanan ◽  
Brian R. Phelan ◽  
Erik H. Lenzing
Keyword(s):  
Mobile Communications ◽  
A Priori ◽  
Estimation Method ◽  
Location Estimation ◽  
Estimation Accuracy ◽  
Time Of Arrival ◽  
Angle Of Arrival ◽  
Feature Vectors ◽  
Area Of Interest ◽  
Estimation System

A method for determining the location of Global Systems for Mobile Communications (GSM) mobile transmitters is proposed. Our approach estimates the location of a source without the use of multilateration or Line-of-Sight (LOS) techniques. A Multipath Characteristic Database (MCD) containing the multipath feature vectors, for each possible transmitter location within an area of interest, is populated via ray-tracing software simulations. The multipath characteristics of interest are angle-of-arrival (AOA) (azimuth) and time-of-arrival (TOA). By minimizing the “distance” between estimated and simulated multipath feature vectors, an estimate for the actual source location can be obtained. The development of the estimation method is presented, followed by a detailed analysis of its estimation accuracy. Since the proposed method utilizes a simulated multipath signature database based upon the knowledge of the environment and the terrain, the need fora priorisoundings from the area of interest is eliminated, thus making this location estimation system suitable for application in denied territories. Location accuracies compare favorably with the requirements for the location of wireless 9-1-1 callers as recommended by the Federal Communications Commission (FCC).

scholarly journals Device-Free Indoor Location Estimation System Using Commodity Wireless LANs

2021 ◽  
Author(s):  
Yuan Zhou ◽  
Minseok Kim ◽  
Hideaki Momose ◽  
Satoru Yasukawa
Keyword(s):  
Low Cost ◽  
Wireless Lans ◽  
Estimation Method ◽  
Location Estimation ◽  
Mimo Channel ◽  
Indoor Location ◽  
Channel Sounder ◽  
Position Detection ◽  
Estimation System ◽  
Device Free

In recent years, since the propagation channel characteristics have been effectively used for applications such as motion sensing, position detection, etc. A great deal of attention is attracted to channel sounding methods easy to utilize using low-cost devices. This paper presents a device-free indoor location estimation method using spatio-temporal features of radio propagation channels using the 2.4-GHz band 3-by-3 MIMO channel sounder developed using commodity wireless LANs. The measurement results demonstrated a reasonable performance of the proposed method with small number of antennas.

scholarly journals GPS Derived Seismic Signals for Far Field Earthquake Epicenter Location Estimation

2021 ◽  
Vol 3 (1) ◽  
pp. 7-12
Author(s):  
Sha’ameri A.Z. ◽  
Wan Aris W.A. ◽  
Musa T.A.
Keyword(s):  
Estimation Method ◽  
Seismic Signal ◽  
The United States ◽  
Location Estimation ◽  
United States Geological Survey ◽  
Time Of Arrival ◽  
Far Field ◽  
Infrastructure Development ◽  
Time Frequency ◽  
Epicenter Location

A reliable epicenter estimation method is proposed for Global Positioning System (GPS) derived seismic signal for far-field regional earthquake. The main contribution is the use of time-frequency analysis to estimate the time of arrival (TOA) using multilateration technique. The data from the 2004 Sumatra Andaman earthquake captured from four GPS continuously operating reference stations (GPS CORS) were used in the analysis. To validate the accuracy of the proposed method, the estimated epicenter location was compared with the data released by the United States Geological Survey (USGS). The estimated location shows an error of about 0.0572 degrees in latitude and 0.2848 degrees in longitude. The proposed analysis method could complement existing seismometer measurements, improve in understanding of geo-seismic phenomena, and plan future infrastructure development.

scholarly journals Pseudorange error analysis for precise indoor positioning system

2017 ◽  
Vol 68 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Marek Pola ◽  
Pavel Bezoušek
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Estimation Method ◽  
Correlation Method ◽  
Signal Propagation ◽  
Ultra Wideband ◽  
Estimation Accuracy ◽  
Time Of Arrival ◽  
Position Measurement ◽  
Direct Path ◽  
Signal Time

Abstract There is a currently developed system of a transmitter indoor localization intended for fire fighters or members of rescue corps. In this system the transmitter of an ultra-wideband orthogonal frequency-division multiplexing signal position is determined by the time difference of arrival method. The position measurement accuracy highly depends on the directpath signal time of arrival estimation accuracy which is degraded by severe multipath in complicated environments such as buildings. The aim of this article is to assess errors in the direct-path signal time of arrival determination caused by multipath signal propagation and noise. Two methods of the direct-path signal time of arrival estimation are compared here: the cross correlation method and the spectral estimation method.

Sensor Deployment for Location-Estimation Coverage

2011 ◽  
Vol 480-481 ◽  
pp. 1161-1166
Author(s):  
J. Ma ◽  
Nobuyoshi Komuro ◽  
Shiro Sakata
Keyword(s):  
Target Location ◽  
Arbitrary Point ◽  
Location Estimation ◽  
Estimation Accuracy ◽  
Sensor Deployment ◽  
Regular Space ◽  
Practical Application ◽  
Coverage Problem ◽  
Estimation System ◽  
The Relationship

Sensor deployment problem for target location estimation is important for sensor networks which fulfill the monitoring tasks. In this paper, we investigate the deployment schemes which guarantee the location estimation accuracy of an arbitrary point within the region, by connecting the location estimation problem with the perspective of k-coverage problem. Our strategies are deploying sensors to guarantee the location-estimation accuracy of an arbitrary point within the monitored region, and to minimize the number of required sensors. Compared with the random deployment, the deterministic deployment provides a better solution to guarantee the location-estimation accuracy over the monitored region. Regular space deployment patterns in 2-dimension, i.e. equilateral triangle, square and regular hexagon, are discussed. The relationship between deployment density and vacancy ratio are derived by mathematical analysis. The derived required sensors deployment density to an arbitrary vacancy ratio for location-estimation coverage provides useful guidelines for sensor network deployment when location-estimation system is required for any practical application.

scholarly journals Developing an Automated System for Simple Estimation of the Direct Damage Amounts from Earthquakes

2021 ◽  
Vol 16 (2) ◽  
pp. 275-286
Author(s):  
Masaki Ikeda ◽  
Qinglin Cui ◽  
Toshihisa Toyoda ◽  
Hiromitsu Nakamura ◽  
Hiroyuki Fujiwara ◽  
...  
Keyword(s):  
Estimation Method ◽  
Automated System ◽  
Estimation Accuracy ◽  
Simple Method ◽  
Financial Measures ◽  
Quantity Index ◽  
Direct Damage ◽  
Technical Requirements ◽  
Physical Assets ◽  
Estimation System

Earthquakes damage physical assets, such as houses, public infrastructure, fields, factories, facilities, as well as inventory of timbers, crops, or products. A direct damage amount is the primary evidence for financial measures to restore and reconstruct the affected areas. Therefore, from a policy perspective, it is essential to estimate it quickly and accurately. Cui et al. have proposed a simple method for estimating direct damages [1, 2]. This study aimed to build a prototype of automatic estimation system and discuss its social implementation. As a result, we succeeded in estimating three earthquakes – the 2018 Osaka Prefecture Northern Earthquake, 2018 Hokkaido Iburi Earthquake, and 2019 Yamagata-oki Earthquake – damage amounts automatically and defining some technical requirements for development. On the other hand, it is necessary to replace the Minryoku index, which is used for Cui’s estimation method and no longer being updated, by new physical assets quantity index, which is continuously updatable. Moreover, the estimation accuracy must be evaluated and improved in finer units of space.

scholarly journals Combination linear lines of position and neural network for mobile station location estimation

2017 ◽  
Vol 13 (7) ◽  
pp. 155014771771738 ◽  
Author(s):  
Chien-Sheng Chen
Keyword(s):  
Mobile Station ◽  
Base Station ◽  
Location Estimation ◽  
Base Stations ◽  
Line Of Sight ◽  
Time Of Arrival ◽  
Angle Of Arrival ◽  
Marquardt Algorithm ◽  
Station Location ◽  
Non Line Of Sight

To enhance the effectiveness and accuracy of mobile station location estimation, author utilizes time of arrival measurements from three base stations and one angle of arrival information at the serving base station to locate mobile station in non-line-of-sight environments. This article makes use of linear lines of position, rather than circular lines of position, to give location estimation of the mobile station. It is much easier to solve two linear line equations rather than nonlinear circular ones. Artificial neural networks are widely used techniques in various areas due to overcoming the problem of exclusive and nonlinear relationships. The proposed algorithms employ the intersections of three linear lines of position and one angle of arrival line, based on Levenburg–Marquardt algorithm, to determine the mobile station location without requiring a priori information about the non-line-of-sight error. The simulation results show that the proposed algorithms can always provide much better location estimation than Taylor series algorithm, hybrid lines of position algorithm as well as the geometrical positioning methods for different levels of biased, unbiased, and distance-dependent non-line-of-sight errors.

Acoustic emission–based impact location estimation on composite structures

2019 ◽  
Vol 18 (5-6) ◽  
pp. 1652-1668
Author(s):  
Jingru Zhou ◽  
V John Mathews ◽  
Daniel O Adams
Keyword(s):  
Acoustic Emission ◽  
Composite Structures ◽  
Estimation Method ◽  
Estimation Algorithm ◽  
Location Estimation ◽  
Accurate Estimation ◽  
Attractive Alternative ◽  
Time Of Arrival ◽  
Impact Location ◽  
The Impact

In this article, an acoustic emission–based impact location estimation algorithm is presented for use with composite structures. The algorithm is formulated as a constrained optimization problem by utilizing sensor locations and times of arrival of impact signals at the sensors. The impact locations are estimated without any information about wave propagation velocity in the structure. A modification of the algorithm to overcome difficulties produced by waveform reflections enables accurate estimation of impact locations close to the structure’s boundaries. The capability of this algorithm to accurately estimate impact locations is demonstrated numerically and experimentally. Experiments performed at different temperatures showed that the algorithm is robust to temperature changes. An automatic time-of-arrival estimation method is also presented. The performance capabilities of the method and its computational simplicity make this approach an attractive alternative to other methods available in the literature for practical structural health monitoring applications.

scholarly journals Device-Free Indoor Location Estimation System Using Commodity Wireless LANs

Telecom ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 181-198
Author(s):  
Yuan Zhou ◽  
Minseok Kim ◽  
Hideaki Momose ◽  
Satoru Yasukawa
Keyword(s):  
Wireless Local Area Network ◽  
Local Area Network ◽  
Estimation Method ◽  
Location Estimation ◽  
Mimo Channel ◽  
Area Network ◽  
Indoor Location ◽  
Position Detection ◽  
Estimation System ◽  
Device Free

In recent years, propagation channel characteristics have been effectively used in several applications such as motion sensing and position detection. Considerable attention has been paid to channel-sounding methods that are easy to utilize using low-cost devices. This paper presents a device-free indoor location estimation method using the spatio-temporal features of radio propagation channels using a 2.4 GHz-band three-by-three multiple-input-multiple-output (MIMO) channel sounder developed using commodity wireless local area network (WLAN). The measurement results demonstrated a reasonable performance of the proposed method with a small number of antennas.

scholarly journals A Novel Parameter Estimation Method Based on a Tuneable Sigmoid in Alpha-Stable Distribution Noise Environments

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3012 ◽  
Author(s):  
Li Li ◽  
Nicolas Younan ◽  
Xiaofei Shi
Keyword(s):  
Parameter Estimation ◽  
Time Delay ◽  
Stable Distribution ◽  
Fractional Fourier Transform ◽  
Impulsive Noise ◽  
A Priori ◽  
Estimation Method ◽  
Fractional Power ◽  
Estimation Accuracy ◽  
Alpha Stable Distribution

In this paper, a novel method, that employs a fractional Fourier transform and a tuneable Sigmoid transform, is proposed, in order to estimate the Doppler stretch and time delay of wideband echoes for a linear frequency modulation (LFM) pulse radar in an alpha-stable distribution noise environment. Two novel functions, a tuneable Sigmoid fractional correlation function (TS-FC) and a tuneable Sigmoid fractional power spectrum density (TS-FPSD), are presented in this paper. The novel algorithm based on the TS-FPSD is then proposed to estimate the Doppler stretch and the time delay. Then, the derivation of unbiasedness and consistency is presented. Furthermore, the boundness of the TS-FPSD to the symmetric alpha stable ( S α S ) noise, the parameter selection of the TS-FPSD, and the feasibility analysis of the TS-FPSD, are presented to evaluate the performance of the proposed method. In addition, the Cramér–Rao bound for parameter estimation is derived and computed in closed form, which shows that better performance has been achieved. Simulation results and theoretical analysis are presented, to demonstrate the applicability of the forgoing method. It is shown that the proposed method can not only effectively suppress impulsive noise interference, but it also does not need a priori knowledge of the noise with higher estimation accuracy in alpha-stable distribution noise environments.

Integrative fMRI-MEG Methods and Optically Pumped Atomic Magnetometers for Exploring Higher Brain Functions

2011 ◽  
pp. 9-17
Author(s):  
Tetsuo Kobayashi
Keyword(s):  
A Priori ◽  
Estimation Method ◽  
Generalized Least Squares ◽  
Spatial Filter ◽  
Estimation Accuracy ◽  
Optically Pumped ◽  
Brain Functions ◽  
Temporal Correlations ◽  
Priori Information ◽  
Beamforming Technique

This chapter introduces a newly developed integrative fMRI-MEG method combined with a spatial filtering (beamforming) technique as a non-invasive neuroimaging method to reveal dynamic processes in the brain. One difficulty encountered when integrating fMRI-MEG analyses is mismatches between the activated regions detected by fMRI and MEG. These mismatches may decrease the estimation accuracy, especially when there are strong temporal correlations among activity in fMRI-invisible and -visible regions. To overcome this difficulty, a spatial filter was devised based on a generalized least squares (GLS) estimation method. The filter can achieve accurate reconstruction of MEG source activity even when a priori information obtained by fMRI is insufficient. In addition, this chapter describes the feasibility of a newly developed optically pumped atomic magnetometer as a magnetic sensor to simultaneously measure MEG and MR signals.

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