IEEE - Aerospace and Electronic Systems - March 2021 - 89

IEEE AES Tutorials

COHERENT RADAR DETECTION IN COMPOUND-GAUSSIAN
CLUTTER: CLAIRVOYANT DETECTORS
K. JAMES SANGSTON
Sensors and Electromagnetic Applications Laboratory
Georgia Tech Research Institute
Smyrna, GA, USA
ALFONSO FARINA
Independent Consultant
Rome, Italy
This paper provides a historical and tutorial overview of
coherent radar target detection in compound-Gaussian
clutter and offers some new perspectives and avenues of
research in this challenging area. It begins with a brief
introduction that motivates the need to develop statistical
models of non-Gaussian clutter and then reviews some of
the physical ideas that led to modeling multivariate radar
clutter statistics by the compound-Gaussian model. With
this starting point, the paper then reviews a series of ideas
that have been developed to describe clairvoyant detectors
in such clutter. The term " clairvoyant " refers to the
assumption that the properties of the clutter are assumed
to be known. In a practical scenario, this assumption does
not hold and adaptive techniques are needed to estimate
clutter properties and implement the detector. Such techniques are guided however by the appropriate clairvoyant
detector structures and hence it is proper to start by studying these detectors. As part of this review, the paper offers
new ways of looking at this problem that suggest new
research topics. This review is limited to the problem of
clairvoyant detection in which the relevant properties of
the clutter are assumed to be known. Adaptive detection
in compound-Gaussian clutter will be the topic of a subsequent tutorial that the authors are preparing.

A SURVEY OF RADAR SYSTEMS FOR MEDICAL APPLICATIONS
STEFANO PISA
ERIKA PITTELLA
EMANUELE PIUZZI
Sapienza University of Rome
Rome, Italy

SENSE AND AVOID FOR UNMANNED AIRCRAFT SYSTEMS
GIANCARMINE FASANO
DOMENICO ACCARDO
ANTONIO MOCCIA
University of Naples " Federico II
Naples, Italy
DAVID MARONEY
The MITRE Corporation
McLean, VA, USA
Sense and avoid (SAA) represents one of the main roadblocks to the integration of unmanned aircraft systems
(UAS) operations by aviation authorities around the world.
This tutorial outlines and reviews the substantial breadth of
SAA architectures, technologies, and algorithms. Starting
from a discussion about what constitutes a UAS and how it
is different than manned aircraft, basic SAA definitions
and taxonomies are discussed. The SAA process is dissected into three fundamental tasks, defined as sensing,
detecting, and avoiding, which are discussed in detail. The
tutorial concludes with a summary of the regulatory and
technical issues that continue to challenge the progress on
SAA, as a key component of reliable UAS operation in civil
aviation authorities (CAAs) around the world.

TUTORIAL XI

A survey of radar systems used in the medical field is presented. First, medical applications of radars are described,
and some emerging research fields are highlighted. Then,
medical radars are analyzed in terms of block diagrams and
behavioral equations and some implementations are shown
as examples. A section is dedicated to the radiating
structures used in these radars. Finally, human safety and
environmental impact issues are addressed. The most investigated medical applications of radars are breast tumor diagnostics and remote monitoring of cardiorespiratory activity.
New fields of interest are physiological liquid detection, and
the monitoring of artery walls and vocal cord movements.
Among the various topologies, continuous wave (CW)
radars have been proven to yield the highest range resolution
MARCH 2021

that is limited only by the system noise while the resolution
of ultra wideband (UWB) and frequency modulated continuous wave (FMCW) radars is also related to the used frequency bandwidth. Concerning the maximum range, UWB
radars have the best performance due to their ability to operate in the presence of environmental clutter. As for the radiating structures, planar antennas are preferred for diagnostic
applications, due to their small dimensions and good matching when placed in contact with the human body. Radar systems for remote monitoring, instead, are designed by using
high gain antennas and taking into account the complex
radar cross section (RCS) of the body.

INTRODUCTORY VIEW OF ANOMALOUS CHANGE DETECTION
IN HYPERSPECTRAL IMAGES WITHIN A THEORETICAL
GAUSSIAN FRAMEWORK
NICOLA ACITO
MARCO DIANI
Accademia Navale
Livorno, Italy
GIOVANNI CORSINI
Universita di Pisa
Pisa, Italy
SALVATORE RESTA
Italian Navy
Exploitation of temporal series of hyperspectral images
is a relatively new discipline that has gained a lot of

IEEE A&E SYSTEMS MAGAZINE

IEEE - Aerospace and Electronic Systems - March 2021

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