Detection of radioactive materials in an urban environment usually requires large, portal-monitor-style radiation
detectors. However, this may not be a practical solution in many transport scenarios. Alternatively, a distributed sensor
network (DSN) could complement portal-style detection of radiological materials through the implementation of arrays
of low cost, small heterogeneous sensors with the ability to detect the presence of radioactive materials in a moving
vehicle over a specific region. In this paper, we report on the use of a heterogeneous, wireless, distributed sensor
network for traffic monitoring in a field demonstration. Through wireless communications, the energy spectra from
different radiation detectors are combined to improve the detection confidence. In addition, the DSN exploits other
sensor technologies and algorithms to provide additional information about the vehicle, such as its speed, location, class
(e.g. car, truck), and license plate number. The sensors are in-situ and data is processed in real-time at each node.
Relevant information from each node is sent to a base station computer which is used to assess the movement of
The development of a scalable and reliable routing protocol for sensor networks is traced from a theoretical beginning
to positive simulation results to the end of veriﬁcation experiments in large and heavily loaded networks.
Design decisions and explanations as well as implementation hurdles are presented to give a complete picture of
protocol development. Additional software and hardware is required to accurately test the performance of our
protocol in ﬁeld experiments. In addition, the developed protocol is tested in TinyOS on Mica2 motes against
well-established routing protocols frequently used in sensor networks. Our protocol proves to outperform the
standard (MINTRoute) and the trivial (Gossip) in a variety of different scenarios.
Given the heightened awareness and response to threats posed to national security, it is important to evaluate, and if possible, improve current measures being taken to ensure our nation’s safety. With terrorism so prevalent in our thoughts, the possible risk of nuclear attacks remains a major concern. Portal monitors are one type of technology that may be used to combat this risk. Their purpose is to detect nuclear materials and, if found, alert first responders to such a discovery.
Los Alamos National Laboratory (LANL) is currently working on an alternative to these costly portal monitors through the Distributed Sensor Network (DSN) project. In collaboration with the University of New Mexico (UNM), this project aims to develop distributed networks of heterogeneous sensors with the ability to process data in-situ in order to produce real-time decisions regarding the presence of radioactive material within the network. The focus of the work described in this paper has been the evaluation of current commercial products available for application deployments, as well as the development of a sensor network in simulation to reduce key deployment issues.