Session 3A2b
Scattering and Rough Surface Scattering
Plane Wave Scattering by a Coated Thin Wire
A. Ike Mowete, Ade Ogunsola, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fast Bistatic ISAR Imaging Simulations for 3D Scattering Center Analysis of Vehicles
Hermann Buddendick, Thomas Eibert, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission Characteristic of Sea Surface Scattered GPS Signal Trapped in Atmospheric Duct
Jin-Peng Zhang, Zhen-Sen Wu, Rong-Xu Hu, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Composite Scattering between Plate and Sea Surface: The Theory and Verified Experiment
Jing-Jian Zhang, Zhen-Sen Wu, Xiao-Bing Wang, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
433
434
435
436
437
434
Progress In Electromagnetics Research Symposium Abstracts, Xi’an, China, March 22–26, 2010
Plane Wave Scattering by a Coated Thin Wire
A. Ike Mowete1 and A. Ogunsola1, 2
1
Department of Electrical and Electronics Engineering
Faculty of Engineering, University of Lagos, Lagos, Nigeria
2
Parsons Group International, Rail Transit Division, London, United Kingdom
Abstract— This paper addresses the problem of scattering by an insulated perfectly conducting
thin-wire, illuminated by a uniform, plane electromagnetic wave. The conductor is modeled
by the usual ‘thin-wire approximation’, and the dielectric insulation, by a volume polarization
current [1, 2], defined in terms of a quasi-static electric field [3], which derives from the distribution
of current along the axis of the bare-wire scatterer through the equation of continuity. The model
for the composite structure then emerges as the sum of two axially directed currents radiating
in free-space. In the moment-method technique subsequently utilized for the solution of the
problem, testing functions, which are critical to specification of the voltage excitation matrix,
are taken as having the two component parts indicated by the choice of model for the coated
scatterer. Computational results obtained for the selected example of a cross-wire [4] suggest
that this analytical approach is valid, as the results reveal that the influence of the coating on
the wire’s bi-static radar cross-section is consistent with those generally reported in the open
literature [5].
REFERENCES
1. Li, X., K. E. K. Drissi, and F. Paladian, “A galerkin moment-method for the analysis of
insulated wires above a lossy half-space,” Annales des Telecommunications, Vol. 58, No. 7/8,
1157–1177, 2003.
2. Richmond, J. H. and E. H. Newman, “Dielectric coated wire antennas,” Radio Science, Vol. 11,
No. 1, 13–20, 1976.
3. Adekola, S. A., A. I. Mowete, and A. Ogunsola, “On the problem of dielectric coated wire
antennas,” Progress In Electromagnetics Research Symposium, Moscow, August 2009.
4. Taylor, C. D., S. M. Lin, and H. V. McAdams, “Scattering from crossed wires,” IEEE Trans.
Antennas and Propagation, Vol. 20, No. 6, 133–136, 1970.
5. More, J. and M. A. West, “Simplified analysis of coated wire antennas and scatterers,” Proceedings of IEE Microwaves, Antennas and Propagation, Vol. 142, No. 1, 14–18, 1995.
Progress In Electromagnetics Research Symposium Abstracts, Xi’an, China, March 22–26, 2010
435
Fast Bistatic ISAR Imaging Simulations for 3D Scattering Center
Analysis of Vehicles
H. Buddendick1 and T. F. Eibert2
1
Institut für Hochfrequenztechnik, Universität Stuttgart, Pfaffenwaldring 47, Stuttgart 70569, Germany
2
Technische Univerität München, Germany
Abstract— One possibility to handle very large and complex environments in deterministic
radio channel simulation approaches is the use of pre-computed and compressed scattering center
models [2]. These models are based on the observation that the EM scattering phenomena at
very high frequencies are typically well focused local effects. A well known technique to describe
these scattering mechanisms is ISAR, Inverse Synthetic Aperture Radar, which can be used to
localize dominating scattering centers.
In our case a 3D bistatic scattering center model is required and consequently also the ISAR
imaging should provide this information. Typically, ISAR imaging is based on multi-dimensional
Fourier processing, which requires costly data acquisition in multiple dimensions as well (e.g.,
frequency and aspect). In this paper a fast simulation approach is presented which requires only
a single aspect simulation run to produce comparable images. The simulation is based on a
high frequency Shooting and Bouncing Rays algorithm, incorporating Geometrical Optics and
Physical Optics field calculations. Similar to [1], the single aspect imaging algorithm exploits
the ray path interactions, inherently known by the ray tracer. Considering a narrowband system
with small aspect variation the contribution of individual rays can be determined analytically.
The approach presented in this paper is adapted to the use in the hybrid GO/PO simulation and
operates on the basis of surface currents. In this way a flexible bistatic evaluation of the ISAR
images is possible.
Figure 1 depicts a 2D example, which shows the good quality of the presented approach. The
final paper will contain a detailed formulation of the ray image contribution for both, horizontal
and vertical polarized imaging.
down-range [m]
rrel [dB]
3
0
2
-10
1
-20
0
-30
-1
-40
-2
-3
-2
-1
0
1
cross-range [m]
2
-3
-2
-1
0
1
2
3
-50
cross-range [m]
Figure 1: Monostatic ISAR image simulation of a passenger car. Classical 2D Fourier processing (left) and
in comparison the result with the fast single shot simulation.
REFERENCES
1. Bhalla, R. and H. Ling, “A fast algorithm for signature prediction and image formation using
the shooting and bouncing ray technique,” IEEE Trans. Antennas Propag., Vol. 43, 727–731,
Jul. 1995.
2. Buddendick, H. and T. F. Eibert, “Radio channel simulations using multiple scattering center
models,” Proc. IEEE AP-S’09, Charleston, SC, Jun. 2009.
436
Progress In Electromagnetics Research Symposium Abstracts, Xi’an, China, March 22–26, 2010
Transmission Characteristic of Sea Surface Scattered GPS Signal
Trapped in Atmospheric Duct
Jin-Peng Zhang, Zhen-Sen Wu, and Rong-Xu Hu
Xidian University, China
Abstract— The atmospheric duct phenomenon forming in anomalous atmosphere environment
can result in the occurring of radar hole and beyond-the-horizon propagation of radar wave.
The real-time inversion technique of atmospheric duct height and intensity makes the real-time
modification of radar wave propagation trace come true, and the performance of radar system
can be improved.
Owing to the advantages of GPS signal, such as all areas and all time, the monitor and inversion
of atmospheric duct using GPS signal receiver are not restricted by time and place, and having
robust feasibility. The inversion of atmospheric duct based on sea surface scattering GPS signal
differs from that based on radar sea clutter, for it does not need the special transmitter and
belongs to passive inversion technique. It is worthy of noting that the atmospheric duct inversion
process using GPS is based on the forward simulation of GPS signal traveling in atmospheric
duct, and the veracity of forward simulation determines the validity of inversion process directly.
The forward propagation model of GPS signal is studied in this paper.
The parabolic wave equation (PWE) is solved in this paper using discrete mixed Fourier transform
(DMFT) with the initial filed which is the sea surface scattering field of GPS signal in a certain
height range. The spatial distribution of path loss of GPS signal scattering from sea surface
is calculated and presented in a 2-D map. The duct trapping effect is obvious in the map,
which validates the scattered GPS signal is trapped and propagates in atmospheric duct for a
certainty. In next step, the power of sea surface scattered GPS signal with respect to the range
can be calculated using the path loss, and it is the very input for the atmospheric duct inversion
algorithm.
Progress In Electromagnetics Research Symposium Abstracts, Xi’an, China, March 22–26, 2010
437
Composite Scattering between Plate and Sea Surface: The Theory
and Verified Experiment
Jing-Jian Zhang1 , Zhen-Sen Wu1 , and Xiao-Bing Wang2
1
2
Xidian University, China
The 802nd Research Institute of Shanghai Academy of Spaceflight Technology, China
Abstract— The study on composite electromagnetic scattering between a target and rough
surface is always of extensive application in the field of EM. In classical research on composite
scattering, the rough surface and target is studied separately. In fact, rough surface and target must be taken as a whole. Not only should the scattering of target and rough surface be
investigated respectively, but also the coupling scattering between them.
In this paper, the dependence of composite scattering on the incident angle is analyzed and the
results of Ref. [1] are verified by an experiment done in Shanghai. The experiment is about
composite scattering between plate targets and smooth sea surface. The results of Ref. [1] get
good agreement with the experiment, which proves the validity of the theory in Ref. [1].
The study on electromagnetic scattering from target in actual background of sea surface provides important theoretic foundation for oceanic surveillance and target detection. So that the
investigation of composite scattering with the diffraction of target fringe taken into account has
important signification of application.
REFERENCES
1. Wu, Z.-S., J.-J. Zhang, and L. Zhao, “Composite electromagnetic scattering from the plate
target above a one-dimensional sea surface: Taking the diffraction into account,” Progress In
Electromagnetics Research, PIER 92, 317–331, 2009.
438
Progress In Electromagnetics Research Symposium Abstracts, Xi’an, China, March 22–26, 2010