scholarly journals A Novel LOS Decision Technique Reflecting 3D DTED for Modeling an Electronic Warfare Environment

2021 ◽  
Vol 11 (1) ◽  
pp. 409
Author(s):  
Jaejoong Lee ◽  
Chiho Lee ◽  
Hyeon Hwi Lee ◽  
Kyung Tae Park ◽  
Hyun-Kyo Jung ◽  
...  
Keyword(s):  
Interpolation Method ◽  
Three Dimensional ◽  
Superior Performance ◽  
Line Of Sight ◽  
Electronic Warfare ◽  
Decision Algorithm ◽  
Elevation Data ◽  
The Republic ◽  
Point Distance ◽  
Terrain Elevation

A new line-of-sight (LOS) decision algorithm applicable to simulation of electronic warfare (EW) is developed. For accurate simulation, the digital terrain elevation data (DTED) of the region to be analyzed must be reflected in the simulation, and millions of datasets are necessary in the EW environment. In order to obtain real-time results in such an environment, a technology that determines line-of-sight (LOS) quickly and accurately is very important. In this paper, a novel algorithm is introduced for determining LOS that can be applied in an EW environment with three-dimensional (3D) DTED. The proposed method shows superior performance as compared with the simplest point-to-point distance calculation method and it is also 50% faster than the conventional interpolation method. The DTED used in this paper is the data applied as level 0 for the Republic of Korea, and the decision of the LOS at approximately 1.8 million locations viewed by a reconnaissance plane flying 10 km above the ground is determined within 0.026 s.

scholarly journals Stochastic C-GNet Environment Modeling and Path Planning Optimization in a Narrow and Long Space

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Jianjian Yang ◽  
Zhiwei Tang ◽  
Xiaolin Wang ◽  
Zirui Wang ◽  
Biaojun Yin ◽  
...  
Keyword(s):  
Path Planning ◽  
Optimal Path ◽  
Three Dimensional ◽  
Test Model ◽  
Environment Modeling ◽  
Grid Network ◽  
Planning Optimization ◽  
Elevation Data ◽  
Dynamic Stochastic ◽  
Terrain Elevation

This study proposes a novel method of optimal path planning in stochastic constraint network scenarios. We present a dynamic stochastic grid network model containing semienclosed narrow and long constraint information according to the unstructured environment of an underground or mine tunnel. This novel environment modeling (stochastic constraint grid network) computes the most likely global path in terms of a defined minimum traffic cost for a roadheader in such unstructured environments. Designing high-dimensional constraint vector and traffic cost in nodes and arcs based on two- and three-dimensional terrain elevation data in a grid network, this study considers the walking and space constraints of a roadheader to construct the network topology for the traffic cost value weights. The improved algorithm of variation self-adapting particle swarm optimization is proposed to optimize the regional path. The experimental results both in the simulation and in the actual test model settings illustrate the performance of the described approach, where a hybrid, centralized-distributed modeling method with path planning capabilities is used.

scholarly journals Improved Path Loss Simulation Incorporating Three-Dimensional Terrain Model Using Parallel Coprocessors

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhang Bin Loo ◽  
Poh Kit Chong ◽  
Kim Yee Lee ◽  
Wun-She Yap
Keyword(s):  
Three Dimensional ◽  
Path Loss ◽  
Accurate Estimate ◽  
Simulation Software ◽  
Experimental Result ◽  
United States Geological Survey ◽  
Disk Model ◽  
Elevation Data ◽  
Computationally Intensive ◽  
Terrain Elevation

Current network simulators abstract out wireless propagation models due to the high computation requirements for realistic modeling. As such, there is still a large gap between the results obtained from simulators and real world scenario. In this paper, we present a framework for improved path loss simulation built on top of an existing network simulation software, NS-3. Different from the conventional disk model, the proposed simulation also considers the diffraction loss computed using Epstein and Peterson’s model through the use of actual terrain elevation data to give an accurate estimate of path loss between a transmitter and a receiver. The drawback of high computation requirements is relaxed by offloading the computationally intensive components onto an inexpensive off-the-shelf parallel coprocessor, which is a NVIDIA GPU. Experiments are performed using actual terrain elevation data provided from United States Geological Survey. As compared to the conventional CPU architecture, the experimental result shows that a speedup of 20x to 42x is achieved by exploiting the parallel processing of GPU to compute the path loss between two nodes using terrain elevation data. The result shows that the path losses between two nodes are greatly affected by the terrain profile between these two nodes. Besides this, the result also suggests that the common strategy to place the transmitter in the highest position may not always work.

scholarly journals On the accuracy of emitter localization method based on multipath exploitation in realistic scenarios

2021 ◽  
Author(s):  
Md Abdullah Al Imran ◽  
Eray Arik ◽  
Yaser Dalveren ◽  
Mehmet Baris Tabakcioglu ◽  
Ali Kara
Keyword(s):  
Real Data ◽  
Theoretical Development ◽  
Practical Implementation ◽  
Performance Bounds ◽  
Electronic Warfare ◽  
Localization Method ◽  
Elevation Data ◽  
Terrain Elevation ◽  
Electronic Support ◽  
Emitter Localization

Abstract This study aims to evaluate the accuracy of a method proposed for passive localization of radar emitters around irregular terrains with a single receiver in Electronic Support Measures (ESM) systems. Previously, only the theoretical development of the localization method was targeted by the authors. In fact, this could be a serious concern in practice since there is no evidence about its accuracy under the real data gathered from realistic scenarios. Therefore, firstly, an accurate ray-tracing algorithm is adapted to the method in order to enable its implementation in practice. Then, scenarios are determined based on the geographic information system (GIS) map generated to collect high resolution digital terrain elevation data (DTED) as well as realistic localization problems for radar emitters. Next, the improved method is tested with simulations, and thus, its performance is verified for practical implementation in Electronic Warfare (EW) context for the first time in the literature. Lastly, based on the simulation results, the performance bounds of the method are also discussed.

CALCULATION OF THE DEPENDENCE OF THE DISTANCE TO THE LOCATED OBJECT FROM THE CORNER POSITION OF THE VEHICLE LINE

2018 ◽  
pp. 14-18
Author(s):  
V. V. Artyushenko ◽  
A. V. Nikulin
Keyword(s):  
Real Time ◽  
Statistical Physics ◽  
Angular Position ◽  
Three Dimensional ◽  
Line Of Sight ◽  
Two Dimensional ◽  
Radar Station ◽  
Flight Mode ◽  
Vector Algebra ◽  
Analytical Expressions

To simulate echoes from the earth’s surface in the low flight mode, it is necessary to reproduce reliably the delayed reflected sounding signal of the radar in real time. For this, it is necessary to be able to calculate accurately and quickly the dependence of the distance to the object being measured from the angular position of the line of sight of the radar station. Obviously, the simplest expressions for calculating the range can be obtained for a segment or a plane. In the text of the article, analytical expressions for the calculation of range for two-dimensional and three-dimensional cases are obtained. Methods of statistical physics, vector algebra, and the theory of the radar of extended objects were used. Since the calculation of the dependence of the range of the object to the target from the angular position of the line of sight is carried out on the analytical expressions found in the paper, the result obtained is accurate, and due to the relative simplicity of the expressions obtained, the calculation does not require much time.

scholarly journals The five axes of the Turtle: symmetry and asymmetry in NGC 6210

2021 ◽  
Author(s):  
William J Henney ◽  
J A López ◽  
Ma T García-Díaz ◽  
M G Richer
Keyword(s):  
Planetary Nebula ◽  
Morphological Study ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Line Of Sight ◽  
Velocity Mapping ◽  
High Ionization ◽  
Motion Measurements ◽  
Five Axes ◽  
Triple Star

Abstract We carry out a comprehensive kinematic and morphological study of the asymmetrical planetary nebula: NGC 6210, known as the Turtle. The nebula’s spectacularly chaotic appearance has led to proposals that it was shaped by mass transfer in a triple star system. We study the three-dimensional structure and kinematics of its shells, lobes, knots, and haloes by combining radial velocity mapping from multiple long-slit spectra with proper motion measurements from multi-epoch imaging. We find that the nebula has five distinct ejection axes. The first is the axis of the bipolar, wind-blown inner shell, while the second is the axis of the lop-sided, elliptical, fainter, but more massive intermediate shell. A further two axes are bipolar flows that form the point symmetric, high-ionization outer lobes, all with inclinations close to the plane of the sky. The final axis, which is inclined close to the line of sight, traces collimated outflows of low-ionization knots. We detect major changes in outflow directions during the planetary nebula phase, starting at or before the initial ionization of the nebula 3500 years ago. Most notably, the majority of redshifted low-ionization knots have kinematic ages greater than 2000 years, whereas the majority of blueshifted knots have ages younger than 2000 years. Such a sudden and permanent 180-degree flip in the ejection axis at a relatively late stage in the nebular evolution is a challenge to models of planetary nebula formation and shaping.

scholarly journals Improving 3D-3D facial registration methods: potential role of three-dimensional models in personal identification of the living

2021 ◽  
Author(s):  
Daniele Gibelli ◽  
Andrea Palamenghi ◽  
Pasquale Poppa ◽  
Chiarella Sforza ◽  
Cristina Cattaneo ◽  
...  
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Personal Identification ◽  
Surveillance Systems ◽  
3D Registration ◽  
Three Dimensional Models ◽  
Point To Point ◽  
Point Distance ◽  
Male Subjects

AbstractPersonal identification of the living from video surveillance systems usually involves 2D images. However, the potentiality of three-dimensional facial models in gaining personal identification through 3D-3D comparison still needs to be verified. This study aims at testing the reliability of a protocol for 3D-3D registration of facial models, potentially useful for personal identification. Fifty male subjects aged between 18 and 45 years were randomly chosen from a database of 3D facial models acquired through stereophotogrammetry. For each subject, two acquisitions were available; the 3D models of faces were then registered onto other models belonging to the same and different individuals according to the least point-to-point distance on the entire facial surface, for a total of 50 matches and 50 mismatches. RMS value (root mean square) of point-to-point distance between the two models was then calculated through the VAM® software. Intra- and inter-observer errors were assessed through calculation of relative technical error of measurement (rTEM). Possible statistically significant differences between matches and mismatches were assessed through Mann–Whitney test (p < 0.05). Both for intra- and inter-observer repeatability rTEM was between 2.2 and 5.2%. Average RMS point-to-point distance was 0.50 ± 0.28 mm in matches, 2.62 ± 0.56 mm in mismatches (p < 0.01). An RMS threshold of 1.50 mm could distinguish matches and mismatches in 100% of cases. This study provides an improvement to existing 3D-3D superimposition methods and confirms the great advantages which may derive to personal identification of the living from 3D facial analysis.

3D Nonlinear Guidance Law for Bank-to-Turn Missile

2011 ◽  
Vol 317-319 ◽  
pp. 727-733
Author(s):  
Shuang Chun Peng ◽  
Liang Pan ◽  
Tian Jiang Hu ◽  
Lin Cheng Shen
Keyword(s):  
Three Dimensional ◽  
Lyapunov Theory ◽  
Line Of Sight ◽  
Rate Model ◽  
Guidance Law ◽  
Terminal Constraints ◽  
Guidance Laws ◽  
3D Guidance ◽  
Guidance Model ◽  
Vector Description

A new three-dimensional (3D) nonlinear guidance law is proposed and developed for bank-to-turn (BTT) with motion coupling. First of all, the 3D guidance model is established. In detail, the line-of-sight (LOS) rate model is established with the vector description method, and the kinematics model is divided into three terms of pitching, swerving and coupling, then by using the twist-based method, the LOS direction changing model is built for designing the guidance law with terminal angular constraints. Secondly, the 3D guidance laws are designed with Lyapunov theory, corresponding to no terminal constraints and terminal constraints, respectively. And finally, the simulation results show that the proposed guidance law can effectively satisfy the guidance precision requirements of BTT missile.

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