Description: The proposed Phase II innovation is the prototype manufacture of an enhanced passive monitoring system that 1) incorporates the same receiving electronics approach that satellite communication hardware uses for improved receiving sensitivity, 2) uses innovative sensor designs that significantly improve measurement sensitivity, and 3) applies wavelet transform image analysis software that automatically identifies wave mode features that are typically lost in conventional signal analysis. This approach results in better source identification and location for the complex signals encountered in structural health monitoring. To increase the sensitivity of the sensors while managing the program risk, a single element approach that uses the sensor resonance and matching networks to increase sensitivity, while still maintaining high fidelity mode identification analysis via the image software development, will be used. With the noise levels of commercially available electronic components in the nanovolt to microvolt range, dynamic range gains of up to 30 dB over conventional designs will be achieved in the electronic design and manufacture of the components. This is a very high bang-for-the-buck approach to gain a huge sensitivity leap for better flaw growth detection. It increases the dynamic range which reduces signal distortion due to amplifier and analog-to-digital converter saturation caused by the wide range of amplitudes encountered in passive monitoring, while lowering the voltage noise level to increase sensitivity. The signal analysis software uses wavelet transforms to turn raw 2D signals into 3D images that are rich in the information they contain. Analyzing images in 3D space for pertinent information opens a vast array of analyses that greatly enhance the feedback to the user of the technology in a fully automated manner that can be almost instantaneous in communicating the source of energy release events in the structure being monitored.

Benefits: Passive SHM of payloads in transit from point of manufacture to launchpad to space to final station whether orbiting or operating on a moon or planet where constraints on power, weight, and footprint are paramount. Monitoring of space vehicles and orbiting stations for space debris impacts. SHM of composite pressure vessels, composite materials, and other large metallic and composite structures, and Lunar Gateway.

Monitoring of Navy, Coast Guard, and Commercial Shipping hull structures for crack propagation at sea, Navy submarine pressure vessels, and composite HP air tanks. Monitoring Navy and commercial aircraft fuselage, wings, and large structural elements for crack propagation in flight. Petrochemical Ind. – Leak detection in piping and aboveground storage tanks.