Hierarchical network development of wireless passive sensors

Design and implementation of wireless sensor systems is one of the important issues in aerospace technologies. It has wide range of applications such as monitoring different parameters in aircraft engines, satellites indoor and outdoor conditions as well as environmental data in moon and other planets in space exploration activities. In most of these applications, it is not possible to utilize active sensors due to operation failure in harsh conditions. In this article, design and implementation of a system consist of both active and passive sensors is studied.