MULTI SENSOR DATA FUSION
by Edward Waltz and James Llinas,
Artech House Radar Library, ISBN: 0-89006-277-3, 464 pages, 1990
This book is devoted to a rapidly developing area of research and development, which involves
significant integration of a number of research disciplines. The initial acquaintance with multisensor
data fusion technology surprisingly involves more interdisciplinary relations than expected.
Communications and decision theories are related to epistemology and uncertainty management.
Estimation theory, digital signal processing and computer science are applied in parallel with artificial
intelligence.
The book gives a thorough introduction into the taxonomy of functional architectures of the
multisensor data fusion systems and defense applications. Contemporary sensors, sources and
communications links are presented and sensor management is depicted. Data fusion for state
estimation is separately discussed in the context of target tracking applications. An important part of
the book covers military concepts of situation and threat assessment. The discussion on
implementation approaches for situation and threat assessment is very useful for all specialists
working in this area. They will find in the book data fusion system architecture design guidelines, how
to model such systems and how to evaluate their performance. The emerging role of artificial
intelligence techniques is also presented.
This book is an important introduction to multisensor data fusion technology and its application in
military command, control, and intelligence operations. The presentation is given at a system-level. It
could be useful to all specialists working in the area of data fusion and C4I systems development.
INFORMATION WARFARE PRINCIPLES AND OPERATIONS
by Edward Waltz
Artech House Radar Library, ISBN: 0-89006-511-X, 380 pages, 1998
The book presents a system engineering-level introduction in the field of Information Warfare. It
provides an overview of the emerging threats in the information space to commercial, civil, and
military information systems. It describes how these threats can be identified and how contemporary
C4I systems can be protected.
An important part of the book is devoted to a detailed consideration of components, principles,
technologies, and tactics of the information warfare. Three areas critical to success are studied:
Information Dominance, Information Defense, and Information Offense. Their comprehensive
discussion provides engineers, system operators and information technology users with an

understandable overview of the quantification of information, and with deductive and inductive
processes that create knowledge. An essential technical background in data mining is given here. All
information security technologies are thoroughly discussed including encryption, authorization, and
attack detection. In addition, possible information attack technologies, including physical,
infrastructure, and perceptual methods, are also analyzed. The book could be of interest for all
specialists working in the area of C4I systems development, as well as to students of information
warfare and information operations.
BAYESIAN MULTIPLE TARGET TRACKING
by Lawrence D. Stone, Carl A. Barlow, Thomas L. Corwin,
Artech House Radar Library, ISBN: 1580530249, 300 pages, October 1999
The book is devoted to one of the currently most popular areas of theory and practice – Multiple
Target Tracking. The well known problem in this area is related to the significant uncertainty in
regard to the relevance of the used stochastic models, and the correctness of their application for
target position and motion prediction over time. Most of the up-to-date target tracking approaches
result in algorithms, which are effective in presence of high amount of data and significant rates of
their accumulation. Unfortunately, very often in reality this is not the case. Facing real world
problems, the authors focus their attention on the case of low data collecting rates and low signal-to-
noise ratio, which is the most wide spread situation currently.
Having in mind that in electronic warfare environments most of the sensors provide ambiguous
information about the number of targets and their state, the authors propose Bayesian inference
approach as basic theoretical framework for design and development of effective tracking algorithms.
Following this path, a general solution of the tracking problems in conditions of insufficient sensor
resources is developed. Thus, the use of Bayesian inference framework provides a base for successful
design and development of mathematically sound algorithms for dealing with up-to-date tracking
problems involving multiple closely spaced targets, multiple netted sensors, and multiple moving
platforms. Respectively, such powerful tracking method as non-linear Multiple Hypothesis Tracking
is thoroughly discussed. Also, the Theory of Unified Tracking approaches is presented as a promising
instrument for successful development of multiple target tracking algorithms in cases of critical
uncertainty.
The book contains many illustrative examples, concept descriptions, and specific algorithms. Cases
with nonlinear target behavior models, non-Gaussian measurement error distributions, low scanning
rates, low signal to noise ratios and multiple closely spaced targets are under special consideration.
The authors treat a number of topics such as the problem of multiple target detection and tracking; the
case for the Bayesian inference; single target tracking; Bayesian filtering; Kalman filtering; discrete
Bayesian filtering; classical multiple target tracking; general multiple hypothesis tracking; classical
multiple hypothesis tracking; multiple target tracking without contacts or association; general multiple
target model; relationship to multiple hypothesis tracking; the theoretical foundations for likelihood

ratio detection and tracking; as well as implementation issues.
The book might be of significant interest for students, specialists and professionals working in field of
reliable situation and threat assessment on the base of effective multisensor data fusion. It will be
especially useful for people searching effective procedure for crisis, conflict and collision avoidance,
conflicts prevention and crisis management on the base of reliable data processing. The approach
offered in the book for dynamic objects state estimation and prediction in case of significant volatility,
uncertainty, complexity and ambiguity is an effective instrument for solving real world problems.
MULTITARGET/MULTISENSOR TRACKING:
APPLICATIONS AND ADVANCES - VOLUME III
by Yaakov Bar-Shalom and William Dale Blair
Artech House Radar Library, Approx. 460 pages, Available in July 2000
The book is a significant addition to previous fundamental authors’ works in the area of Multisensor
Multitarget Tracking. It provides the most up-to-date available information and guidance to
development of new practical and effective solutions for sensor data processing systems. For people
searching for innovative solutions it discusses the most important contemporary problems of advanced
target tracking applications, giving the reader a chance to be in touch with the forefront of this
professional area.
In particular, the book presents the modern viewpoint on multisensor tracking problems, on the
allocation of insufficient resources, and on advanced hardware and software development. A thorough
consideration of assignment techniques for multitarget data association is presented. It includes the
incorporation of the Nearest Neighbor Joint Probabilistic Data Association algorithm into the
Interacting Multiple Model estimator. It also considers non-linear filtering for fusing target’s
kinematic state measurements and target’s signature measurements. A Variable Structure Interacting
Multiple Model (VS-IMM) estimator combined with an Assignment algorithm for tracking multiple
ground targets is thoroughly discussed. The effective use of MTI data obtained from an airborne
sensor is studied and the obtained results could be of great interest for professionals involved in radar
data processing.
The book includes an in-depth discussion of techniques, related to corrupted radar tracking
performance. It presents ways of modeling and simulating ECMs, using computers. A detailed signal
processing model is proposed to help sonar/radar waveform optimization for reliable tracking. A
comprehensive introduction to variable structure estimators is provided and an accession of their
practical applications is made.
The book covers practical aspects of multisensor tracking and sensor resource allocation; survey of
assignment techniques for MTT; IMM estimator with nearest neighbor; joint probabilistic data

association; tracking; closely-spaced, deformable objects; tracking for Ballistic Missile Defence; joint
target tracking and identification: an application of nonlinear filtering; ground target tracking with
topography-based variable structure IMM Estimator; radar signal processing for tracking; optical
sensor signal processing for tracking; modeling of electronic countermeasures for multitarget tracking
and data association; sonar/radar waveform design for optimal tracking performance; engineer’s guide
to variable structure estimators for tracking.
The book will be of great interest for designers and systems engineers, involved in sensor data
processing for wide area of application. It could be especially useful for professionals, engaged in
R&D of multisensor data fusion algorithm for conflict prevention, collision avoidance and crisis
management in air, ground and sea applications. Also, it could be of interest for specialists applying
dynamic objects state estimation in variety of public safety ensuring systems.
SENSORS FOR PEACE
APPLICATIONS, SYSTEMS AND LEGAL REQUIREMENTS FOR MONITORING IN
PEACE OPERATIONS
Editors: Jurgen Altmann, Horst Fisher and Henny van der Graaf
United Nations Publication, New York, 1998, ISBN 92-9045-130-0
The book is devoted to one of the vital problems of peace operations: monitoring of situations and
threats in unstable, uncertain, complicated and deceptive environments. The main goal of the authors
is to analyze the use of unattended ground sensor systems in four important areas of application, and
to provide recommendations on the employment of sensors in peace operations. The importance of
this publication is unquestionable. There is no clearer example of practical effectiveness of the system
of multiple sensor utilization and its potential contribution to increasing international security. But in
our point of view, the most valuable contribution of this publication are lessons learned in the sensor
system utilization during difficult times of particular peace operations.
The presentation begins with thorough consideration of operational aspects of the use of sensors in
peace operations. It clearly shows how sensors fit into different tasks carried out by peace forces, and
how sensor systems and personnel requirements interact. Special attention is paid to the use of sensors
under various circumstances, i.e., in mobile tasks such as patrolling. Very useful is the presentation of
operational requirements cost estimation and organizational set-up. Using many tables with technical
characteristics and rich illustrations, the authors introduce the reader into the essence of the sensor
systems information fusion and the specifics of their application.
An important evaluation of the Questionnaire on Application of Ground Sensors during peacekeeping
Operations is presented next. The study covers up-to-date technology capability utilization, systems
optimization, and efficiency improvement. It describes capabilities provided by systems already
available on the market. The cost of such systems and their development are specified in detail.

The legal aspects of ground sensor utilization in peace operations are discussed at the end of the book.
International law aspects are carefully investigated and the need for new rules in regulating the sensor
systems implementation is confirmed.
Finally, a set of important conclusions and recommendations are formulated. Options for decision-
makers and policy recommendations for United Nations, as well as for contributing states are given.
Thus, the book may be regarded as an important study, which establishes close connections between
multisensor data fusion and security issue. It will be useful for specialists, working in the area of
multisensor data fusion engineering applications.

INFORMATION FUSION TERMINOLOGY
Information Fusion encompasses theory, techniques and tools conceived and employed for exploiting
the synergy in information acquired from multiple sources (sensor, databases, information gathered by
human, etc.). The objective is that the resulting decision or action is in some sense better (qualitatively
or quantitatively, in terms of accuracy, robustness etc.) than it would be possible if any of these
sources were used individually, i.e., without exploiting synergy. (B. V. Dasarathy, Dynetics, Inc.)
In the process of fusion events, activities and movements are correlated and analyzed as they occur in
time and space. The purpose is to determine location, identity and status of individual objects
(equipment and units), to assess the situation, to determine qualitative and quantitative characteristics
of threats to coalition operations, and to detect patterns in activities that reveal intent or capability.
Specific technologies are required to refine, direct and manage the information fusion capabilities.
In relation to Multisensor Data Fusion, Multi-Sensor Collaboration is performed as an innovative
technical approach, which is engaged to eliminate limitations in the current capabilities of sensors.
Sensor collaboration technology must address ground, airborne and spaceborne systems and processes
in a fully distributed environment. A special goal is the development of a predictive intelligence
assessment of the warfighter's battlespace situation.
Data Fusion is a process dealing with the association, correlation, and combination of data and
information from single and multiple sources to achieve refined position and identity estimates,
complete and timely assessment of situations and threats, as well as their significance.
Often, data fusion is accompanied by sensor management. A sensor management system is any
system which provides automatic control of a suite of sensors or measurement devices. In general, a
sensor management system must answer the following four questions: 1) What sensor? 2) Which
service? 3) Where to point? 4) When to start? The sensor manager output is a schedule defined over
an interval of time where each entry of the schedule is a scheduling vector containing the answers to
these questions.
In practice, Data Fusion is a formal framework in which are expressed means and tools for the
alliance of data originating from different sources, and for the exploitation of their synergy in order to
obtain information whose quality cannot be achieved otherwise. More philosophically (B. V.
Dasarathy, Dynetics, Inc.) - "When you borrow information from one source, it’s plagiarism; When
you borrow information from many, it’s information fusion"
Concerning multisensor fusion, the general problem can be restated as: how is it possible to observe a
dynamical scene with a set of sensors by controlling their configuration, i.e. their sequencing, as well
as the scheduling of the resources, be they directly attached to the sensors or centralized. Evaluating
the reliability of different information sources is crucial when the received data reveals some
inconsistencies and we have to choose among various options. In fact, the reliability of the source
affects the credibility of the information and vice-versa. It is necessary to develop systems that deal
with couples (information, source) rather than with information alone.

Decentralized distributed detection and decision fusion systems attract significant interest due to the
increasing need to employ multiple sensors for surveillance, intelligence and communications. Some
of the motivating factors are the natural advantages of distributed detection over centralized detection:
reliability, survivability, increases in required coverage of surveillance, and reduction in
communications bandwidth.
One purpose of Sensor Fusion is to realize new sensing architecture by integrating multi-sensor
information and to develop hierarchical and decentralized architecture for recognition such as human
beings further. As a result, more reliable and multilateral information can be extracted, which can
realize high-level recognition mechanism.
INTRODUCTORY LITERATURE:
D.S. Lawrence, D. Stone, et.al., Bayesian Multiple Target Tracking, (Artech House Radar Library,
1999).
A. Zembower, "Emerging Trends in Sensor Data Management," in Proceedings of the 15th Annual
AESS/IEEE Dayton Section Symposium Sensing the world: Analog Sensors and Systems Across the
Spectrum (May 1998), 71-78.
M.S. Markin, et.al., Data Fusion and Data Processing (The Report of the Defence and Aerospace
Foresight Working Party, 1997).
K. Varshney, Distributed Detection and Data Fusion (Springer 1996).
J. Manyika and H. Durrant-Whyte, Data Fusion and Sensor Management: A decentralized information
theoretic approach (Ellis Horwood, 1994).
D.L. Hall, Mathematical Techniques in Multisensor Data Fusion (Artech House, 1992).
M.A. Abidi and R. C. Gonzalez, Data Fusion in Robotics & Machine Intelligence (Academic Press,
1992).
J.J. Clark and A.L. Yuille, Data Fusion for Sensory Information Processing Systems (Kluwer
Academic Publishers, 1990).
E. Waltz and J. Llinas, Multisensor Data Fusion (Artech House, 1990).
INTERNET ADDRESSES FOR REFERENCES:
http://www-datafusion.cma.fr/fund/definitions.html
http://www.inform.unian.it/area/cognitive/Fusion.htm

http://dflwww.ece.drexel.edu/research/dds
http://roadway.ivhs.washington.edu/pubs/fusion_abstract.htm
INTERNATIONAL SOCIETY OF INFORMATION FUSION EVENTS:
SPIE's International Symposium on AeroSense - Signal Processing, Sensor Fusion and Target
Recognition IX, Orlando, FL, USA.
World Computer Congress - WCC'2000, Beijing, China, August 21-25, 2000.
Threats, Countermeasures, and Situational Awareness: Teaming for Survivability - Symposium and
Exhibition, Virginia Beach, June 20-22, 2000.
Fusion2000 - Third International Conference on Information Fusion, Paris, France, July 10-13, 2000.
Fusion of Soft Computing & Hard Computing in Industrial Applications, Session at SMC2000,
Nashville, TN, USA, October 8-11, 2000

Central Laboratory for Parallel Processing
The Central Laboratory for Parallel Processing (CLPP) was established in 1985 as a Coordination
Center of Informatics and Computer Technology (CCICT). The main idea was to coordinate research
in the field of Computer Science and Computer Technologies conducted by scientists from the
Bulgarian Academy of Sciences, Bulgarian universities and R&D institutes closely connected with
industry, as well as to promote international cooperation in the area of theoretical and practical
problems of the new generation of computers. Special emphasis was placed on the following issues:
l high performance computer systems and algorithms for parallel processing
l distributed computer systems
l computer networks
l intelligent man-machine interface, etc.
Annually, the scientists from the Laboratory publish approximately 140 papers, and about hundred of
them are published in refereed international journals and proceedings of high quality international
conferences. In 1996, CCICT was renamed as Central Laboratory for Parallel Processing. CLPP is
headed by a Director, a Deputy Director and a Scientific Secretary. Currently, Prof. D.Sc. Ivan Dimov
is Director of CLPP. General and scientific policy of the Laboratory is formulated by Board of
Directors, including all Department heads, and the 24-member Scientific Council. Currently, the
CLPP consists of a Computer Center and six departments:
l Distributed computing systems and networks
l Parallel algorithms
l Scientific computing
l High performance computer architectures
l Linguistic modeling
l Mathematical methods for sensor information processing.
The Department of Distributed Systems and Networking was founded in 1985. It is chaired by
Prof. Dr. K. Boyanov, Corresponding member of the Academy of Sciences. Main areas of research
within the department are:
l Network Protocols
l Parallel and Distributed Heterogeneous Computing Environments
l High Speed Local Area Networks
l Data Messaging
l Broadband communications

l Parallel interpretation of object-oriented programs
l Dynamic load balancing in distributed systems
A concept of distributed computer architecture with reconfigurable communications interconnection
was developed. Based on this architecture several high performance computers with modular structure
and up to 64 processors were constructed. Architecture allowing flexible use of high-speed networks
has been suggested. The department is coordinator of the Bulgarian Academic Network. The studies
accomplished in the Department are aimed at the creation of a methodology for effective parallel
interpretation of wide range of applications which would merge the advantages of parallel processing
and the specification of user applications by means of graphical (diagrammatic) high level object-
oriented language. Currently, the Department of Distributed Systems and Networking participates in
several international joint research programs such as ACTS, NATO Science for Peace, as well as in
bilateral reasearch projects on parallel algorithms. Its staff consists of one corresponding member, two
full professors, three associate professors, eight research fellows, and four support specialists.
The main research activities of the Department of Parallel Algorithms are in the following areas:
l New efficient parallel algorithms;
l Monte Carlo algorithms (differential and integral equations, linear algebra,
spectral problems, data processing);
l Fractal methods for image processing;
l Computational geometry and topological graph theory;
l Applications of parallel algorithms and supercomputing (large-scale problems,
parallel and/or vector computers, clusters of workstations).
The Department of Parallel Algorithms participates in several international joint research programs
financed by the Commission of the European Communities, NATO Science for Peace and other
sources.
The Department organizes a number of international scientific meetings - conferences, workshops and
seminars. The traditional IMACS Seminar on Monte Carlo methods is jointly organized by IMACS
and the Central Laboratory for Parallel Processing.
The Department of Parallel Algorithms employs one academician, one full professor, four associate
professors, six scientific researchers, and one supporting specialist.
The Department of Scientific Computing was founded in 1997. The major objectives of the research
activities of the Department are as follows:
(i) to develop new efficient numerical methods which are robust with respect to the
problem and method parameters, and which can also perform efficiently on modern
computer systems, including parallel ones;

(ii) to implement the developed algorithms and to create software tools, as well as to
test them on benchmark problems close to the advanced requirements of real-life
computer simulation practice.
Currently the Department of Scientific Computing participates in several international joint research
programs financed by EU, NSF-USA, Volkswagen, etc. The successfully finalized in 1998
Copernicus Project "High Performance Computing in Geosciences. Safety of Constructions with
Respect to Rock Deformations and Movements" represents the abilities of the group from the
Department of Scientific Computing to perform high level research in an interdisciplinary
international research team.
The Department organizes the biannual Workshop on "Large-Scale Scientific Computations".
The Department of Scientific Computing numbers two associated professors, two senior research
fellows and one supporting researcher.
The High Performance Computer Architecture (HPCA) Department at the Central Laboratory for
Parallel Processing was founded in 1998 at the Bulgarian Academy of Sciences and is chaired by
Prof. Vladimir Lazarov who led High Performance Systems and Parallel Algorithms Laboratory
existing since 1986. The research and development areas cover:
l Computational Models;
l Advanced Computer Architectures;
l Computer Simulation of HPCA.
The department staff consists of eight researchers: three associate professors and five senior
researchers.
The Department of Linguistic Modeling was set up in 1987 as Linguistic Modeling Laboratory. The
formation of the Laboratory was intended to meet the modern trends in the research and application of
natural language processing. The Department's main tasks are:
l Computer modeling of basic fragments of the Bulgarian language - lexical and
grammatical resources. A computer dictionary of Bulgarian (70 000 units) was
prepared in two versions.
l Computer modeling of Slavonic languages. (Computer dictionary of Russian -
100 000 units).
l Computer processing of multilingual resources (Bilingual aligned Corpora base
is compiled for French-English, French-Bulgarian and English-Bulgarian
parallel texts: 2.5 Million words).
l Methods and tools for knowledge based machine aided translation (System for

machine-aided human translation with generation of explanations in natural
language).
The Department of Linguistic Modeling have actively participated in twelve international projects.
The personnel of the Department of Linguistic Modeling enlists nine researchers, two of them being
associate professors and five research fellows.
The Mathematical Methods for Sensor Data Processing Department (MMSDP) at the Central
Laboratory for Parallel Processing (CLPP) is founded in 1988 at the Bulgarian Academy of Sciences.
It specializes in solving complex theoretical and practical problems involving sensor data processing
for Bulgarian Ministry of Education and Science, Ministry of Industry, Ministry of Defense, Air
Traffic Control Authorities, and Sofia Technical University.
Employing modern mathematical approaches and high performance computers, the researchers in the
Department provide R&D products for solving basic problems of sensor data processing systems:
automation, performance improvement, initial operator education and training. The efforts of the
research team are directed both to new applications and to technological upgrade of existing sensor
data processing systems. Significant experience in developing and applying effective sensor data
processing approaches and methods for real-time multisource kinematic and attribute data correlation,
association, estimation and fusion is accumulated. The main R&D areas cover the following
directions of real-time sensor data processing:
l Multiple Sensor Multiple Target Tracking (track initiation, measurements data
association, measurements and tracks fusion)
l Stochastic systems identification and hybrid estimation
l Automated collision warning/avoidance in navigation conflicts (object’s optimal
control)
l Parallel MTT algorithm design and implementation.
In 1999, the department consists of 13 researchers: two full professors, two associate professors and
seven senior researchers. Two of them have D.Sc. degrees and nine have Ph.D. degrees.
More information on Central Laboratory for Parallel Processing is available at its Web site:
http://www.acad.bg/
BACK TO TOP
© 1999, ProCon Ltd, Sofia
Information & Security. An International Journal
e-mail: infosec@mbox.digsys.bg