scholarly journals X-Band Radar Cross-Section of Tandem Helicopter Based on Dynamic Analysis Approach

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 271
Author(s):  
Zeyang Zhou ◽  
Jun Huang
Keyword(s):  
Dynamic Analysis ◽  
Cross Section ◽  
Dynamic Characteristics ◽  
Elevation Angle ◽  
Radar Cross Section ◽  
Passage Time ◽  
Analysis Approach ◽  
Observation Angle ◽  
Attitude Angle ◽  
X Band

In order to study the radar signature of a tandem helicopter in the X-band, a dynamic analysis approach (DAA) is presented to determine its radar cross-section (RCS) under different influence factors. The basic passage time, rotation speed, observation angle, rotor disk inclination, fuselage attitude angle and Doppler feature are studied and discussed in detail. The results show that the dynamic characteristics of the rotor RCS will bring significant changes to the peak and average values of the helicopter RCS. Within a given observation angle range, a larger elevation angle is undesirable for helicopter stealth. The inclination of the rotor disc will affect the many small peaks and local fluctuations of the helicopter RCS. The positively increased attitude angle will have an undesirable effect on the average RCS and dynamic characteristics of the helicopter. The DAA is feasible and effective for studying the radar cross-section of a tandem helicopter.

SRR-Based High Gain Microstrip Antenna with Low Radar Cross Section

2014 ◽  
Vol 644-650 ◽  
pp. 4092-4094
Author(s):  
Shu Juan Wang
Keyword(s):  
Cross Section ◽  
Microstrip Antenna ◽  
Radar Cross Section ◽  
High Gain ◽  
Ring Resonators ◽  
Analysis Method ◽  
Split Ring ◽  
Split Ring Resonators ◽  
X Band ◽  
Scattering Wave

The split ring resonators (SRR) is designed to work at X band and its equivalent medium parameters are estimated by using the equivalent analysis method. The high gain microstrip antenna, which is based on Photonic BandGap (PBG) structure, is also studied. To make the scattering wave deviates mirror direction and reduce the out-band Radar Cross Section (RCS) without affecting the performance of antenna, the designed SRR is used as the cover of PBG structure microstrip antenna. The results show that the forward gain of PBG structure antenna is 0.8 dB higher than the tradition antenna. After the SRR covers on the PBG structure antenna, the gain of antenna is unchanged and the RCS of the mirror direction decreases for all incident angles, and the most decrement is 21.05 dB.

scholarly journals Comparison of Three Different Styles of Submarine Sails on Electromagnetic Scattering under the Detection of Airborne Radar

2018 ◽  
Vol 17 ◽  
pp. 02003
Author(s):  
Ji Liu ◽  
Peilin Huang ◽  
Yaodong Zhao ◽  
Jinzu Ji ◽  
Fengli Xue
Keyword(s):  
Cross Section ◽  
Electromagnetic Scattering ◽  
Pitch Angle ◽  
Elevation Angle ◽  
3D Models ◽  
Radar Cross Section ◽  
Physical Optics ◽  
Airborne Radar ◽  
Range Analysis ◽  
Radar Antenna

This paper studies radar cross section of submarine sails on the water. Under the detection of the enemy’s airborne radar, considering the motion of the submarine, the sail model of radar pitch angle incidence range analysis is established. By using CATIA software, the 3D models of AKULA sail, SUBOFF sail and VICTOR sail are built. On the basis of the physical optics method and the equivalent currents method, the scattering characteristics of sails RCS(radar cross section) are simulated under X radar band. Through the microwave anechoic chamber test, this paper verifies the accuracy of the combination of the physical optics method and the equivalent electromagnetic flow method. The influence of the distance from the airborne radar to the sail on the pitch angle of the electromagnetic wave is discussed, with the elevation angle of the radar antenna varies. Then, we illustrate the characteristics of circumferential direction RCS of the sail under different pitch angles. Finally, the mean RCS of the sail at a given pitch angle is simulated. The results show that the AKULA sail is considerably superior to SUBOFF sail and VICTOR sail on stealth performance with the pitch angle less than 4° . But when the pitch angle exceeds 10°, the SUBOFF sail can be given priority.

scholarly journals Analysis of the Radar Cross Section of an X-band Active Transponder

2011 ◽  
Vol 22 (3) ◽  
pp. 327-335
Author(s):  
Ji-Hwan Hwang ◽  
Soon-Gu Kwon ◽  
Joong-Sun Won ◽  
Yi-Sok Oh
Keyword(s):  
Cross Section ◽  
Radar Cross Section ◽  
X Band

Radar Cross Section Measurements and Simulations of a Model Airplane in the X-band

PIERS Online ◽  
2009 ◽  
Vol 5 (4) ◽  
pp. 377-380 ◽  
Author(s):  
Inácio M. Martin ◽  
Mauro Angelo Alves ◽  
G. G. Peixoto ◽  
Mirabel C. Rezende
Keyword(s):  
Cross Section ◽  
Radar Cross Section ◽  
X Band

scholarly journals Signal Propagation in Soil Medium: A Two Dimensional Finite Element Procedure

2021 ◽  
Author(s):  
Frank Kataka Banaseka ◽  
Kofi Sarpong Adu-Manu ◽  
Godfred Yaw Koi-Akrofi ◽  
Selasie Aformaley Brown
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Scattered Field ◽  
Radar Cross Section ◽  
Transverse Magnetic ◽  
Arbitrary Cross Section ◽  
Observation Angle ◽  
Two Dimensional ◽  
Total Field ◽  
Dimensional Finite Element

A two-Dimensional Finite Element Method of electromagnetic (EM) wave propagation through the soil is presented in this chapter. The chapter employs a boundary value problem (BVP) to solve the Helmholtz time-harmonic electromagnetic model. An infinitely large dielectric object of an arbitrary cross-section is considered for scattering from a dielectric medium and illuminated by an incident wave. Since the domain extends to infinity, an artificial boundary, a perfectly matched layer (PML) is used to truncate the computational domain. The incident field, the scattered field, and the total field in terms of the z-component are expressed for the transverse magnetic (TM) and transverse electric (TE) modes. The radar cross-section (RCS), as a function of several other parameters, such as operating frequency, polarization, illumination angle, observation angle, geometry, and material properties of the medium, is computed to describe how a scatterer reflects an electromagnetic wave in a given direction. Simulation results obtained from MATLAB for the scattered field, the total field, and the radar cross-section are presented for three soil types – sand, loam, and clay.

scholarly journals Insights into wind turbine reflectivity and radar cross-section (RCS) and their variability using X-band weather radar observations

2021 ◽  
Vol 14 (5) ◽  
pp. 3541-3560
Author(s):  
Martin Lainer ◽  
Jordi Figueras i Ventura ◽  
Zaira Schauwecker ◽  
Marco Gabella ◽  
Montserrat F.-Bolaños ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Cross Section ◽  
Wind Turbines ◽  
Weather Radar ◽  
Radar Cross Section ◽  
Least Square ◽  
Clear Correlation ◽  
Radar Observations ◽  
X Band ◽  
Polarimetric Weather Radar

Abstract. The increasing need of renewable energy fosters the expansion of wind turbine sites for power production throughout Europe with manifold effects, both on the positive and negative side. The latter concerns, among others, radar observations in the proximity of wind turbine (WT) sites. With the aim of better understanding the effects of large, moving scatterers like wind turbines on radar returns, MeteoSwiss performed two dedicated measurement campaigns with a mobile X-band Doppler polarimetric weather radar (METEOR 50DX) in the northeastern part of Switzerland in March 2019 and March 2020. Based on the usage of an X-band radar system, the performed campaigns are up to now unique. The main goal was to quantify the effects of wind turbines on the observed radar moments, to retrieve the radar cross-section (RCS) of the turbines themselves and to investigate the conditions leading to the occurrence of the largest RCS. Dedicated scan strategies, consisting of PPI (plan position indicator), RHI (range–height indicator) and fixed-pointing modes, were defined and used for observing a wind park consisting of three large wind turbines. During both campaigns, measurements were taken in 24/7 operation. The highest measured maxima of horizontal reflectivity (ZH) and RCS reached 78.5 dBZ and 44.1 dBsm, respectively. A wind turbine orientation (yawing) stratified statistical analysis shows no clear correlation with the received maximum returns. However, the median values and 99th percentiles of ZH show different enhancements for specific relative orientations. Some of them remain still for Doppler-filtered data, supporting the importance of the moving parts of the wind turbine for the radar returns. Further, we show, based on investigating correlations and an OLS (ordinary least square) model analysis, that the fast-changing rotor blade angle (pitch) is a key parameter, which strongly contributes to the variability in the observed returns.

scholarly journals Hybrid Deflection of Spoiler Influencing Radar Cross-Section of Tailless Fighter

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8459
Author(s):  
Zeyang Zhou ◽  
Jun Huang
Keyword(s):  
Cross Section ◽  
Electromagnetic Scattering ◽  
Deflection Angle ◽  
Elevation Angle ◽  
Radar Cross Section ◽  
Control Surface ◽  
Linear Mode ◽  
Linear Dynamic ◽  
The Given ◽  
Control Surfaces

With the continuous development of advanced fighters towards tailless and flying wing layouts, diverse control surfaces have become the mainstream design. To study the influence of spoiler control surface on the radar cross-section (RCS) of a tailless fighter, a calculation method is presented. The deflection angle of the spoiler is controlled by the fixed mode, linear mode, and smooth mode. The results show that the opening action of the spoiler will break the original stealth characteristics of the aircraft at the key azimuth angles of the head and tail. As the elevation angle increases, this adverse effect will spread to the side. The influence of the different dynamic deflection modes of the spoiler on the aircraft RCS is analyzed. Compared with the linear dynamic deflection mode, the smooth dynamic deflection mode is conducive to the reduction in the average RCS at the given head azimuth. The presented method is effective to study the influence of the spoiler deflection on the electromagnetic scattering characteristics of the tailless aircraft.

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