Fusion in Signal Processing - Information Fusion in Signal and Image Processing - page 13

Chapter 2
Fusion in Signal Processing
2.1. Introduction
There has been a significant evolution in sensors available today in terms of perfor-
mance and quality as well as the associated signal processing. This constant progress,
from the perspective of both hardware and software, provides us with increasingly
dense and complex elements of information, that differ in nature and reliability, for
example, the multi-mode radar, capable of performing several tasks such as detecting,
tracking or identifying targets.
Whether in the field of military applications, with the improved performances of
portable devices, where speed, range, maneuverability, stealth, signal jamming and
group movements have a direct impact on the surveillance system's efficiency, or in
other fields of signal processing, there are major demands: a surveillance or diagnosis
system must have a reactivity close to real-time, without loss of performance, and must
offer as quickly as possible a situation assessment, with a reliability and an accuracy
known to the operator. The use of a single type of sensor quickly became obsolete and
the multi-sensor approach, associated with information fusion, progressively became
prevalent for the creation of a comprehensive system to assist decision making.
This multi-sensor approach introduced new concepts, many of them inherent to
how the systems functioned, such as control, decision making and communications
management, in order to co-ordinate the various components and to ensure a certain
consistency. Because of disparities in response time, accuracy or operating conditions
between the sensors, managing such a system is complex in many regards.