Journal or Book Title
We have developed an ultrasonic array sensor useable for locating air leaks in manned spacecraft and have found that this sensor locates leaks in a 1-m2 plate to within 2 cm. The sensor consists of a 63-element multiplexed array plus a reference element, all constructed from a single PZT disc and a printed circuit board. Cross-correlations of signals from the array elements with signals from the single reference element provide a measurement of the leak noise passing through the spacecraft skin under the array. A spatial Fourier transform reveals the dominant direction of propagation. Triangulation from multiple sensor locations can be used to find the source of the leak.
Holland, Stephen D.; Roberts, Ronald A.; Chimenti, Dale E.; and Song, Junho, "An ultrasonic array sensor for spacecraft leak direction finding" (2006). Aerospace Engineering Publications. 10.