Hyper-Fuzzy Modeling and Control for
Bio-Inspired Radar Processing
Omar M. Salim
1
, Hoda S. Abdel-Aty-Zohdy
2
, Mohamad A. Zohdy
2
1
High Institute of Technology, Benha University, Egypt;
2
School of Engineering and Computer Science, Oakland University, Rochester, MI 48309;
Abstract: Modern RF Radar signal processing has been
receiving much attention for wide range of domains that
include industrial, environmental, and military
applications. Inherently, the received raw
spatial-temporal signals can be 1-D, 2-D, or 3-D and are
usually of uncertain nature, because of changing
conditions and optical background variations. In this
paper, we apply novel concepts for hyper-neural theory
that allow for incorporation of variables attribute
definitions and uncertainties for the purpose of effective
evidential learning and subsequent key output features
determination in the radar processing. Application
to wide-band angle of arrival data sets at several carrier
frequencies has been carried out in order to illustrate
the strengths as well weakness of the approach. Using
interval set-based operations together with
segmentation of the data is proved useful and gave good
sensitivity of detection.
Keywords: Fuzzy Logic, Membership function, Neural
Networks
1. Introduction
As modern radar signals and systems become
more sophisticated in terms of its short pulse
waveform optimization and wideband nature, the
receivers need to have surveillance and direction
finding capabilities. Characterization and
identification of the threat signals by bounding the
angle of arrival (AOA) to specific interval enables
location of the source of threat signal [1, 2].
Current wideband digital receiver systems are
typically based on a channelization [1]. This
channelization can be implemented to have wideband
coverage [2]. For a phased array system,
implementation requires similar set of components
following each antenna element, which may be
impractical. This system needs a controller to scan
through channels to function as a wideband receiver
[2].
Phased array receiver system is the extensively
used modern day technology. The multiple antenna
elements provide not only the spatial-temporal
capability, but also an extra gain due to coherence
and less confounding compared to single antenna
receiver system [2].
The AOA can be for example measured by
processing the spatial-temporal data, using the Fast
Fourier Transform (FFT) in 2-D for time-frequency
conversion. The peak FFT component in the
frequency bin contains the frequency and power
information of the input signal. Likewise, the peak
FFT component in the spatial FFT bin contains the
direction and power information of the input signal.
Applications involving direction surveillance, the
phased array is usually scanned through a range of
positive and negative angles [2]. Applications
involving direction surveillance, the phased array is
usually scanned through a range of angles. For these
applications, microwave lens [3], Butler Matrix [4],
Blass Matrix, and time delay line [5] are among the
analog beam forming methods that can be used.
Digital time delay line and FIR filter are among the
digital beam forming implementation methods [6].
In this paper, a hyper-neural technique is
proposed, where the time series data points are
processed directly to obtain the target AOA from the
information embedded in the measured 2-D
spatial-temporal patterns.
These techniques which are based on learning,
adaptation, and testing are representative of Fuzzy
Logic Systems (FLS), Neural Networks (NN), and
hybrid systems like Adaptive Neuro-fuzzy Inference
System (ANFIS).
2. Fuzzy Logic Systems
Fuzzy logic has gained attention of researchers
for last couple of decades. It has displaced
conventional technologies in different scientific and
system engineering applications, especially in pattern
recognition, signal processing communication,
integrated circuit manufacturing, biomedical systems,
and mostly overall control systems [7]. The same
fuzzy technology, in approximation reasoning form,
is resurging also in the information technology, where
it is now giving support to decision-making,
bio-inspired systems, and expert systems with
powerful reasoning capacity especially for limited
rules [7]. The fuzzy sets were presented by L.A.
Zadeh in 1965 to process / manipulate data and
information affected by unprobabilistic
uncertainty/imprecision [7]. These were designed to
mathematically represent the vagueness and
uncertainty of linguistic problems; thereby obtaining
formal tools to work with intrinsic imprecision in
different problems; it is considered a generalization
of the classic set theory. Intelligent Systems based on
fuzzy logic are fundamental tools for nonlinear
978-1-4244-6578-1/10/$26.00 ©2010 IEEE 392