Using acoustic images for human identification

An acoustic electronic scanning array is developed to acquire acoustic images from a person. On the basis of pulse- echo techniques, multifrequency acoustic images are obtained for a set of positions of a person (front, front with arms outstretched, back and side). Two uniform linear arrays with 15 λ/2-equispaced sensors have been employed, using different spatial apertures in order to reduce sidelobe levels. Work frequencies have been designed on the basis of the main lobe width, the grating lobe levels and the frequency responses of people and of sensors. Finally, for a case of study with 6 people, the acoustic profiles, formed by all images acquired, are evaluated and compared in a mean square error sense. According to the obtained results, this system will be able to be used for biometric applications.