SIMULATION OF REFLECTIONS FROM SURFACE-DISTRIBUTED OBJECTS ON EXAMPLE OF FRAGMENT OF UNDERLYING SURFACE

2019 ◽  
pp. 22-26
Author(s):  
M. A. Stepanov
Keyword(s):  
Real Time ◽  
Electromagnetic Waves ◽  
Geometric Model ◽  
Angular Position ◽  
Underlying Surface ◽  
Distributed Objects ◽  
Spherical Coordinate ◽  
Flight Mode ◽  
Straight Line ◽  
Low Altitude

The paper considers the problem of the synthesis of a low-point model of the relief of the underlying surface. The model can be used to conduct semi-null simulation when the radar is operating in low-altitude flight mode. A method for defining a relief in the form of a piecewise broken approximation is proposed. An algorithm is presented that allows real-time, for a given relief, to calculate for each of the elements of the resolution in range its angular position and angular dimensions. These parameters determine the expectation of the angular noise and the width of their probability density, respectively. The ability to work in real time is provided using a straight line in a spherical coordinate system when defining the relief. The recommendations on the choice of a geometric model from the previously justified family are given. The synthesized models provide a given form of the correlation functions of angular noise and adequately replace reflections from distributed objects. Geometric models can be used as the basis for matrix simulators of reflected electromagnetic waves.

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.

Influence of the Type of the Underlying Surface Forest Cover on the Level of SNS Radio Signals Reflected from the Surface at Low-Altitude Aircraft Flight

2019 ◽  
pp. 64-74
Author(s):  
N.E. Zubov ◽  
A.A. Eshchenko ◽  
S.S. Demin ◽  
G.E. Maslennikova ◽  
S.V. Ivanenko
Keyword(s):  
Noise Level ◽  
Electromagnetic Waves ◽  
Forest Cover ◽  
Signal To Noise Ratio ◽  
Elevation Angle ◽  
Underlying Surface ◽  
Multiple Reflections ◽  
Aircraft Flight ◽  
Radio Signals ◽  
Low Altitude

The purpose of the study was to analyze the influence of the type of the underlying surface forest cover on the level of SNS radio signals reflected from the surface and, accordingly, on the aircraft user equipment efficiency at low-altitude flying. By mathematical simulation, we analyzed the dependences of the signal-to-noise ratio on the elevation angle of navigation spacecraft of the working constellation and the aircraft flight altitude for different types of forest cover. Findings of research show that the rugged barren terrain is characterized by the highest noise level, while the lowest noise level is typical for the thin forest. This can be explained by the fact that most electromagnetic waves penetrate deep into the forest, where they are absorbed due to multiple reflections. Moreover, the thicker the forest cover, the lower the degree of absorption and the higher the noise level.

ABOUT INVARIANCE OF ANGLE NOISE DISTRIBUTION PARAMETERS BY AN ARBITRARY N-POINT GEOMETRIC MODEL TO VIEWING ANGLE

2019 ◽  
pp. 32-35
Author(s):  
V. V. Artyushenko ◽  
A. V. Nikulin
Keyword(s):  
Regular Polygon ◽  
Geometric Model ◽  
Sea Surface ◽  
Noise Distribution ◽  
Viewing Angle ◽  
Distributed Objects ◽  
Software Complex ◽  
The Earth ◽  
Distribution Parameters ◽  
Equal Power

In this article we consider a problem of reliable modeling of echo signals and angle noise of distributed objects using twodimensional geometric models with random statistically unrelated signals. The conditions that ensure the invariance of distribution parameters of the angle noise generated by an arbitrary N-point configuration of a two-dimensional geometric model are obtained. In the particular case of a model whose emitters are supplied with signals of equal power, the conditions of invariance are reduced to the location of the model points on the plane in the form of a regular polygon. These results can be used to synthesize mathematical models used for simulating reflections from distributed objects and for developing a hardware-software complex for the simulation of electromagnetic fields reflected from the Earth surface, atmospheric inhomogeneities, the sea surface, etc.

scholarly journals Programmable Reflection–Transmission Shared‐Aperture Metasurface for Real‐Time Control of Electromagnetic Waves in Full Space

2021 ◽  
pp. 2100149
Author(s):  
Lei Bao ◽  
Qian Ma ◽  
Rui Yuan Wu ◽  
Xiaojian Fu ◽  
Junwei Wu ◽  
...  
Keyword(s):  
Real Time ◽  
Electromagnetic Waves ◽  
Real Time Control ◽  
Time Control

scholarly journals Dynamical visualization of anisotropic electromagnetic re-emissions from a single metal micro-helix at THz frequencies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Notake ◽  
T. Iyoda ◽  
T. Arikawa ◽  
K. Tanaka ◽  
C. Otani ◽  
...  
Keyword(s):  
Real Time ◽  
Electromagnetic Waves ◽  
Electromagnetic Compatibility ◽  
Smart Antenna ◽  
Dynamical Behavior ◽  
Measurement Techniques ◽  
Spatial Evolution ◽  
Frequency Spectra ◽  
3D Objects ◽  
Current Oscillations

AbstractThe capability for actual measurements—not just simulations—of the dynamical behavior of THz electromagnetic waves, including interactions with prevalent 3D objects, has become increasingly important not only for developments of various THz devices, but also for reliable evaluation of electromagnetic compatibility. We have obtained real-time visualizations of the spatial evolution of THz electromagnetic waves interacting with a single metal micro-helix. After the micro-helix is stimulated by a broadband pico-second pulse of THz electromagnetic waves, two types of anisotropic re-emissions can occur following overall inductive current oscillations in the micro-helix. They propagate in orthogonally crossed directions with different THz frequency spectra. This unique radiative feature can be very useful for the development of a smart antenna with broadband multiplexing/demultiplexing ability and directional adaptivity. In this way, we have demonstrated that our advanced measurement techniques can lead to the development of novel functional THz devices.

scholarly journals Huber-Based Robust Unscented Kalman Filter Distributed Drive Electric Vehicle State Observation

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 750
Author(s):  
Wenkang Wan ◽  
Jingan Feng ◽  
Bao Song ◽  
Xinxin Li
Keyword(s):  
Kalman Filter ◽  
Real Time ◽  
Degrees Of Freedom ◽  
Unscented Kalman Filter ◽  
State Parameter ◽  
State Observation ◽  
Straight Line ◽  
Distributed Drive Electric Vehicle ◽  
Huber Method ◽  
Yaw Moment

Accurate and real-time acquisition of vehicle state parameters is key to improving the performance of vehicle control systems. To improve the accuracy of state parameter estimation for distributed drive electric vehicles, an unscented Kalman filter (UKF) algorithm combined with the Huber method is proposed. In this paper, we introduce the nonlinear modified Dugoff tire model, build a nonlinear three-degrees-of-freedom time-varying parametric vehicle dynamics model, and extend the vehicle mass, the height of the center of gravity, and the yaw moment of inertia, which are significantly influenced by the driving state, into the vehicle state vector. The vehicle state parameter observer was designed using an unscented Kalman filter framework. The Huber cost function was introduced to correct the measured noise and state covariance in real-time to improve the robustness of the observer. The simulation verification of a double-lane change and straight-line driving conditions at constant speed was carried out using the Simulink/Carsim platform. The results show that observation using the Huber-based robust unscented Kalman filter (HRUKF) more realistically reflects the vehicle state in real-time, effectively suppresses the influence of abnormal error and noise, and obtains high observation accuracy.

A framework for near real-time ROM stockpile modelling to improve blending efficiency

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shi Zhao ◽  
Tien-Fu Lu ◽  
Larissa Statsenko ◽  
Benjamin Koch ◽  
Chris Garcia
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Laser Scanning ◽  
High Efficiency ◽  
Reference Model ◽  
Geometric Model ◽  
Mining Industry ◽  
Management Systems ◽  
Content Type ◽  
Ore Grade

Purpose In the mining industry, a run-of-mine (ROM) stockpile is a temporary storage unit, but it is also widely accepted as an effective method to reduce the short-term variations of ore grade. However, tracing ore grade at ROM stockpiles accurately using most current fleet management systems is challenging, due to insufficient information available in real time. This study aims to build a three-dimensional (3D) model for ROM stockpiles continuously based on fine-grained grade information through integrating data from a number of ore grade tracking sources. Design/methodology/approach Following a literature review, a framework for a new stockpile management system is proposed. In this system, near real-time high-resolution 3D ROM stockpile models are created based on dump/load locations measured from global positioning system sensors. Each stockpile model contains a group of layers which are separated by different qualities. Findings Acquiring the geometric shapes of all the layers in a stockpile and cuts made by front wheel loaders provides a better understanding about the quality and quality distribution within a stockpile when it is stacked/reclaimed. Such a ROM stockpile model can provide information on predicating ore blend quality with high accuracy and high efficiency. Furthermore, a 3D stockyard model created based on such ROM stockpile models can help organisations optimise material flow and reduce the cost. Research limitations/implications The modelling algorithm is evaluated using a laboratory scaled stockpile at this stage. The authors expect to scan a real stockpile and create a reference model from it. Meanwhile, the geometric model cannot represent slump or collapse during reclaiming faithfully. Therefore, the model is expected to be reconcile monthly using laser scanning data. Practical implications The proposed model is currently translated to the operations at OZ Minerals. The use of such model will reduce the handling costs and improve the efficiency of existing grade management systems in the mining industry. Originality/value This study provides a solution to build a near real-time high-resolution multi-layered 3D stockpile model through using currently available information and resources. Such novel and low-cost stockpile model will improve the production rates with good output product quality control.

Real-time UAV Trajectory Prediction for Safety Monitoring in Low-Altitude Airspace

2019 ◽  
Author(s):  
Matteo Corbetta ◽  
Portia Banerjee ◽  
Wendy Okolo ◽  
George Gorospe ◽  
Dmitry G. Luchinsky
Keyword(s):  
Real Time ◽  
Safety Monitoring ◽  
Trajectory Prediction ◽  
Low Altitude
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