Radar Simulation Research Articles

Electronic warfare system simulation based on SystemVue

Electronic warfare simulation can allow the realistic evaluation of the performance of equipments and techniques, and it can also allow the realistic training of individuals under conditions that, in real life, might kill them. We propose a new scheme of EW simulation system based on SystemVue. This paper mainly expounds the structure of system and the key technology of subsystem establishment. As a proof of concept, a radar electronic reconnaissance simulation experiment is explained in this paper. And the results verify the feasibility of the scheme.

MATLAB-Based 3-D MoM and FDTD Codes for the RCS Analysis of Realistic Objects [Testing Ourselves

Three-dimensional (3-D) MATLAB-based codes are developed for radar cross-section (RCS) modeling and simulation (MODSIM) using method of moments (MoM) and finite-difference time-domain (FDTD) approaches. Any object can realistically and comparatively be investigated.

SAR imaging of a topography-induced current front in a tidal channel

A quasi-linear dark-bright feature was observed on a TerraSAR-X synthetic aperture radar (SAR) image acquired in the area of Pearl River Estuary (PRE), China, on 25 October 2010. Examining the detailed local bathymetry chart, we find that the feature is collocated with major axis of Lingding Channel in the waterway of PRE. In the study, we first run a 3-D hydrodynamic model to simulate the tidal currents within PRE, and then used the simulated current and local wind data as input to run a radar simulation model to calculate the variation of normalized radar cross section induced by these parameters. Ocean model simulation shows that surface currents were parallel to the major axis of the channel at the satellite overpass time. Radar model simulation results show good agreement between the simulated and actual SAR images. The quasi-linear dark-bright feature on the SAR image was found to be due to the surface current convergence and divergence caused by the bathymetry-induced tidal current variation.

Reconstruction of cloud geometry using a scanning cloud radar

Abstract. Clouds are one of the main reasons of uncertainties in the forecasts of weather and climate. In part, this is due to limitations of remote sensing of cloud microphysics. Present approaches often use passive spectral measurements for the remote sensing of cloud microphysical parameters. Large uncertainties are introduced by three-dimensional (3-D) radiative transfer effects and cloud inhomogeneities. Such effects are largely caused by unknown orientation of cloud sides or by shadowed areas on the cloud. Passive ground-based remote sensing of cloud properties at high spatial resolution could be crucially improved with this kind of additional knowledge of cloud geometry. To this end, a method for the accurate reconstruction of 3-D cloud geometry from cloud radar measurements is developed in this work. Using a radar simulator and simulated passive measurements of model clouds based on a large eddy simulation (LES), the effects of different radar scan resolutions and varying interpolation methods are evaluated. In reality, a trade-off between scan resolution and scan duration has to be found as clouds change quickly. A reasonable choice is a scan resolution of 1 to 2\\degree. The most suitable interpolation procedure identified is the barycentric interpolation method. The 3-D reconstruction method is demonstrated using radar scans of convective cloud cases with the Munich miraMACS, a 35 GHz scanning cloud radar. As a successful proof of concept, camera imagery collected at the radar location is reproduced for the observed cloud cases via 3-D volume reconstruction and 3-D radiative transfer simulation. Data sets provided by the presented reconstruction method will aid passive spectral ground-based measurements of cloud sides to retrieve microphysical parameters.

Time-Domain Simulation of Along-Track Interferometric SAR for Moving Ocean Surfaces.

A time-domain simulation of along-track interferometric synthetic aperture radar (AT-InSAR) has been developed to support ocean observations. The simulation is in the time domain and based on Bragg scattering to be applicable for moving ocean surfaces. The time-domain simulation is suitable for examining velocities of moving objects. The simulation obtains the time series of microwave backscattering as raw signals for movements of ocean surfaces. In terms of realizing Bragg scattering, the computational grid elements for generating the numerical ocean surface are set to be smaller than the wavelength of the Bragg resonant wave. In this paper, the simulation was conducted for a Bragg resonant wave and irregular waves with currents. As a result, the phases of the received signals from two antennas differ due to the movement of the numerical ocean surfaces. The phase differences shifted by currents were in good agreement with the theoretical values. Therefore, the adaptability of the simulation to observe velocities of ocean surfaces with AT-InSAR was confirmed.

Simulation of ISAR Imaging for a Space Target and Reconstruction Under Sparse Sampling via Compressed Sensing

Simulation of inverse synthetic aperture radar (ISAR) imaging of a space target and reconstruction under sparse sampling via compressed sensing (CS) are developed. The numerical bidirectional analytic ray tracing (BART) method is employed to compute the polarized scattering from an electrically large target. With multiorbit and multistation imaging modes, 2-D and 3-D ISAR images are acquired, leading to information retrieval of the space target, such as shape, structure, attitude, etc. CS is introduced into the reconstruction of ISAR images under sparse sampling. As an example, the models of the Aura satellite and the X-37B orbital test vehicle are presented for ISAR imaging and reconstruction.

Developing and Evaluating Ice Cloud Parameterizations for Forward Modeling of Radar Moments Using in situ Aircraft Observations

AbstractObserving ice clouds using zenith pointing millimeter cloud radars is challenging because the transfer functions relating the observables to meteorological quantities are not uniquely defined. Here, the authors use a spectral radar simulator to develop a consistent dataset containing particle mass, area, and size distribution as functions of size. This is an essential prerequisite for radar sensitivity studies and retrieval development. The data are obtained from aircraft in situ and ground-based radar observations during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) campaign in Alaska. The two main results of this study are as follows: 1) An improved method to estimate the particle mass–size relation as a function of temperature is developed and successfully evaluated by combining aircraft in situ and radar observations. The method relies on a functional relation between reflectivity and Doppler velocity. 2) The impact on the Doppler spectrum by replacing measurements of particle area and size distribution by recent analytical expressions is investigated. For this, higher-order moments such as skewness and kurtosis as well as the slopes of the Doppler spectrum are also used as a proxy for the Doppler spectrum. For the area–size relation, it is found that a power law is not sufficient to describe particle area and small deviations from a power law are essential for obtaining consistent higher moments. For particle size distributions, the normalization approach for the gamma distribution of Testud et al., adapted to maximum diameter as size descriptor, is preferred.

Polarimetric Variables Retrieval with Clutter Suppression for Staggered PRT Sequences

AbstractThis paper presents a procedure to filter ground clutter from dual-polarized staggered pulse repetition time (PRT) radar data in simultaneous and alternating transmission modes for polarimetric variables retrieval. The filter is designed in the time domain so that polarimetric variables such as the differential phase () and the copolar correlation coefficient () can be estimated directly from clutter-filtered time series data using a conventional method. In the case of the simultaneous mode, a single filter is used for both channels to maintain the signal correlation after filtering. For the alternating mode, because the polarizations are transmitted in different waveforms, two separate filters are required. However, the filters are designed so that the responses of the filters to the signals are identical within the extended Doppler range. Based on radar simulation, it is shown that the method can provide accurate retrieval of polarimetric variables even in the case of strong clutter contamination. Also, the performance of the method is illustrated on dual-polarized staggered PRT ⅔ data from the NASA dual-frequency dual-polarized Doppler radar (D3R).

The radar signal simulation based on the analysis of Pulse-Doppler radar for digital signal processing implementation in the Matlab environment

Introduction. The complexity of modern radar (RLS) due to their versatility and the need to adapt to the interference situation is constantly changed. The models to test the basic ideas to be implemented in the radar are required. It is important to consider the main stages of the simulation of the radar signal based on the analysis of radar operation. Problem statement. The creation of a universal analytical model to build a radar signal in Matlab is considered. Theoretical results. Stages and results of the radar signal simulation are presented and based on the analysis of pulse – Doppler radar. Basic analytical relations ofthe task are given. Features of simulation when signals of additive fluctuation noise and clutter together with the echo target signals arrive are considered. Conclusion. As a result of analysis of radar interference conditions on the basis of existing relations an optimum variant model of radar signal in Matlab environment is reached. This is the basis for further evaluation of the digital processing effectiveness of the radar signal to background noise and interference (clutter), namely to determine the distance to targets and target’s speeds. . The main advantages of the Mellin transform using for recognizing signals at different scales are presented is conclusions.

Design and Implementation of Netted Radar Training Simulator

With the rapid development of information technology and deeply evolution of air-to-ground combat mode, the combat between air targets and netted radar will be an important component of future warfare. Design and development of netted radar training system is historically inevitable. This paper aims to design and develop networking radar training simulator system. We have studied and designed the system structure and function. With deeply analysis of the key model of the system, the training simulator was implemented by object-oriented technology. This paper mainly introduces the overall design of netted radar training simulator and the simulation method to realize the key models.

A Novel Technique for Radar Depth Sounding of Fast Outlet Glaciers and Ice-Sheet Margins

The surface clutter simulator and the digital filter technique are developed for sounding and imaging of a subsurface stratified structure with arbitrary ice surface roughness of fast outlet glaciers and ice-sheet margins, which provides a new insight into the strong surface clutter reduction. The radar signal simulation method developed by employing Kirchhoff approximation of rough surface scattering and the ray tracing of geometric optics theory can give clear understanding of electromagnetic (EM) wave radiation and propagation through multilayer stratified media and support the interpretation of radar actual observations for retrieving good information on ice bed and internal layers. The radar sounder echo simulator can calculate the EM scattering from ice internal multilayer rough interfaces and identify whether deeper layers or ice-bed nadir echoes masked by a strong surface off-nadir echo still return to the radar receiver or not, which offers an important tool for designing and optimizing radar system performance. The numerical spline interpolation technique is proposed to discretize the 3-D real ice topography into a suitable triangulated mesh for obtaining higher accurate radar simulation data compared with the facet method. The digital filter technique can be complementary to conventional processing methods in order to distinguish an ice bed from a strong surface clutter with an extremely crevassed rough surface in Antarctica and Greenland. Ice data processing results of certain outlet glaciers' topography are demonstrated. The presented unified data analysis methodology can be also applied to planetary exploration.

Programmable Control on Initial Phase of Oscillation Using AD9854

Based on in depth study of internal structure and external interface of AD9854, applying singlechip to control its interior programmable register and related accumulator through parallel interface of AD9854, to explore feasible control method, after reiterative experiment, achieved programmable control on initial phase of oscillation of output pulse of AD9854. This method had applied on some radar echo signal simulator, fulfilled fixed objective echo signal synthesizing.

Optimum Arrival Routes for Flight Efficiency

With the development of aircraft equipment, conventional navigation is the shift from performance based navigation (PBN). As is known, conventional navigation is based on ground-based navigation aids; however, PBN is based on aircraft avionics and performance. In this paper, a new method called Point Merge System (PMS) considered as one of PBN procedures will be introduced. PMS has many benefits related to fuel savings and emission reductions by implementing Continuous Descent Approaches (CDAs). A new PMS standard arrival route (STAR) model will be designed in radar simulation and it will be suggested.

An element-free Galerkin method for ground penetrating radar numerical simulation

An element-free Galerkin method (EFGM) is used to solve the two-dimensional (2D) ground penetrating radar (GPR) modelling problems, due to its simple pre-processing, the absence of elements and high accuracy. Different from element-based numerical methods, this approach makes nodes free from the elemental restraint and avoids the explicit mesh discretization. First, we derived the boundary value problem for the 2D GPR simulation problems. Second, a penalty function approach and a boundary condition truncated method were used to enforce the essential and the absorbing boundary conditions, respectively. A three-layered GPR model was used to verify our element-free approach. The numerical solutions show that our solutions have an excellent agreement with solutions of a finite element method (FEM). Then, we used the EFGM to simulate one more complex model to show its capability and limitations. Simulation results show that one obvious advantage of EFGM is the absence of element mesh, which makes the method very flexible. Due to the use of MLS fitting, a key feature of EFM, is that both the dependent variable and its gradient are continuous and have high precision.

A Computational Approach to Air Traffic Controller Situation Awareness Based on Multi-sensor Data

Good situation awareness(SA) is highly important for air traffic controllers(ATCos) to maintain the safe, orderly and expeditious flow of air traffic. If ATCos' situation awareness can be accurately monitored and alerted before it has been lost, it will be highly possible to improve ATCos' performance and prevent accidents. At present, many ways exist to evaluate ATCos' situation awareness, but they are basically diagnostic and retrospective methods, early warning and forecasting cannot be achieved. ATCos' situation awareness could be affected by many factors, but it can be demonstrated by some performance and physiological indicators. In order to improve the prediction accuracy of SA, multi-sensor data which are relevant to ATCos' situation awareness will be collected by radar control simulation experiment, psychological measurement, and expert ratings. The ultimate aim of the research is to establish SA computational models by two different approaches, which address demonstration indicators and contributing variables of the above multi-sensor data respectively. An evaluation of the two prediction Models will also be made. The research results are expected to provide supports for monitoring ATCos' situation awareness.

一种航迹跟踪雷达模拟系统软件设计与实现

In order to meet the need of a high-fidelity and interactivity of tracking radar simulation requirements,this paper sets up a kind of path tracking radar simulation software based on Visual C++.The basic theory,structure design and implementation of the software system are analyzed.According to the statistics results of the radar targets scattering,the paper presents the scattering statistical model containing the target echo model of noise and clutter,builds the aircraft's motion model,and sets up the batch and track filtering algorithm.Then,the simulation system for the functional design and working process is introduced,and emphatically the software implementation to solve the technical difficulties is introduced,including the goal and the mountain shade of judgment and the synthetic technology of the target echo.Finally,this paper presents the main interface and the function window of the simulation system.In general computer the software running results show that the calculating response time is less than 0.1s,A scope and PPI image update smooth,flicker-free,good portability.The simulation of mountains clutter and targets is vivid,software running is fluent,and has good real-time operation,which indicates that the software system can meet the target detection,noise filtering and path tracking requirements of the path tracking radar.

用于生命特征信号识别的模拟系统研制

在生命特征信号处理的研究中，由于人体状态、姿势及位置等的不同，使得其研究结果产生了很大差异。因此，本文设计了一种基于生物雷达监测系统的用于生命特征信号研究的模拟系统。该系统为生命特征信号的处理研究提供了定量稳定的目标信号，并且其信号频率、幅度等参数连续可调。本系统通过模拟人体的心肺运动，实现了非接触式生命探测实验。通过不同条件下对模拟系统的实验测试，实验结果证明了在不同工况下，该系统具有更好的信噪比，且系统是全局稳定的，提高了系统的实用性。 In the research of life characteristic signal processing, because of different status, postures and positions, the results produce huge difference. Therefore, this paper designs a monitoring system which is based on biological radar simulation system, and it could be used in the study of life cha-racteristic signal. The system provides target signals with stable quantitation for the research of life characteristic signal processing, and the signal parameters such as frequency, amplitude are adjustable. The system realizes the non-contact life detecting experiment through simulating the cardio of human. Through the test of the simulation system under different conditions, the expe-rimental results prove that under different conditions, the system has better SNR and is globally stable, improving the practicability.

Echo Doppler Fidelity’s Verification of Radar Simulator

Radar simulator is a special important instrument in the field of radar test, but the current for the fidelity of the echo of radar simulator validation study is in its infancy. In this paper, the research object is the target’s Doppler, and the simulator fidelity measured by two methods: numerical computation and computing eigenvalues. And the two calculation methods are described in detail on the concrete steps and key issues.

Numerical Study of Borehole Radar for Cliff Imaging

Numerical simulation of borehole radar (BHR) is an efficient and economical method to verify its feasibility before applying it in subsurface imaging. We conducted a physical experiment by using a commercial BHR system in a borehole close to a limestone cliff and used the 2-D finite-difference time-domain (FDTD) simulation to cross-check the observed features of reflection from the cliff wall. For a maximum distance between the borehole and cliff of about 10 m, the time delay of the cliff wall reflection appears at about 170 ns. The simulation agrees well with the experiment, and the accuracy can meet the need for imaging analysis.

Echo simulation of lunar penetrating radar: based on a model of inhomogeneous multilayer lunar regolith structure

Lunar Penetrating Radar (LPR) based on the time domain Ultra-Wideband (UWB) technique onboard China's Chang'e-3 (CE-3) rover, has the goal of investigating the lunar subsurface structure and detecting the depth of lunar regolith. An inhomogeneous multi-layer microwave transfer inverse-model is established. The dielectric constant of the lunar regolith, the velocity of propagation, the reflection, refraction and transmission at interfaces, and the resolution are discussed. The model is further used to numerically simulate and analyze temporal variations in the echo obtained from the LPR attached on CE-3's rover, to reveal the location and structure of lunar regolith. The thickness of the lunar regolith is calculated by a comparison between the simulated radar B-scan images based on the model and the detected result taken from the CE-3 lunar mission. The potential scientific return from LPR echoes taken from the landing region is also discussed.