Structural sensing, structural health monitoring (SHM), structural performance assessment, and health prognosis are integral components of modern structural engineering practice. Due to recent extraordinary levels of development in sensor, communication, and signal processing technologies, it is now possible to measure structural properties and behavior with sufficient clarity to assess damage levels and to predict future courses of structural health. SHM can help the owners, builders, and designers of structures in rational decision-making [1-4]. Possible benefits include enhancing the safety of structures with warnings of impending failures, prompting more efficient use of maintenance resources, and providing information that leads to better designs. In the aerospace industry the benefits of SHM can appear as increased up-time usage rates for aerospace systems and improved designs [5]. SHM measurements can help optimize maintenance activity planning [6]. Financial entities, such as insurance companies and municipal bond markets, make use of the rational assessment of structural conditions and prognoses [79]. Certain high-performance structures, for example, reusable launch vehicles, may not be able to operate effectively without SHM [10-12]. Many relatively low-performance ancillary structures, such as highway signs and light poles, can also benefit from SHM [13].