Detecting cracks and monitoring their growth in bridge structures is an objective of structural health monitoring. Because of the uncertainty as to where such crack might form methods that provide surveillance of a broad area are needed. Monitoring acoustic emission (AE) from the formation and growth of such crack s has been explored as a posibble approach. Issues include differentiating between environmental noises [rain, electromagnetic interference from a variety of sources], structural noise [connector rubbing, crushing of debris and corrosion pruduct in between thr cracks surfaces], and emission from plastic zone formation and crack advance. In addition, whether uninterrupted monitoring is needed or whether strategies that awake dormant sensors can be used dictate whether real-time processing or data mining of massive of data are necessary. (Rak 3)