Sensor processing is a central and an important problem in aerospace/defense, automation, medical imaging, and robotics, to name only a few areas. A surveillance system used in aerospace and defense is an example of a sensor processing system. It uses devices such as infrared sensors, microwave radars, and laser radars that are capable of detecting and tracking flying objects in their observational space. A sensor processing system may employ intelligent and disparate sensors that are distributed logically, spatially, and even geographically. It is then referred to as a distributed sensor network (DSN). The sensor may measure scalar values (e.g., temperature) or vector values (e.g., position in three-dimensional space). The measurements are generally a function of time and/or space. Because of variation in operating environments or other factors, such as aging and communication delays, the measurements may appear contradictory. Although combining the numerous sensor measurements may appear contradictory, it minimizes the uncertainty of measurements and improves reliability and fault tolerance.

There is a wide body of literature on sensor networks and on design, analysis, protocols, and other research-related issues in sensor networks. However, the issues of software development, in particular pedagogical material related to software development in sensor networks, has been left mostly untouched. We present this book to focus on software development in sensor networks. This book provides the basics needed to develop sensor network software and supplements itwith many case studies covering network applications.We also examine howto develop onboard applications on individual sensors, how to interconnect these sensors, and how to form networks of sensors, although the major aim of this book is to provide foundational principles of developing sensor networking software and to critically examine sensor network applications.