Face classification with ultrasonic sensing

The echo of a chirp of ultrasonic energy from an object contains information about the geometry of that object: relative depth of surfaces and approximate area of those surfaces. A human face has complex geometry that produces a distinctive echo. In this paper, we report initial research into whether there is sufficient information in the echo to recognize a face. Potential features for classification are identified using a facial model. The classification results are poor, but encourage future research to find better quality features.