Dimensionality reduction for acoustic vehicle classification with spectral embedding

Classification and identification of moving vehicles from audio signals is of interest in many applications, ranging from traffic flow management to military target recognition. Classification may involve differentiating vehicles by type, such as jeep, sedan, etc. Identification can involve distinguishing specific vehicles, even within a given vehicle type. Since audio data is small compared to, say, video data, multiple audio sensors can be placed easily and inexpensively. However, there are certain obstacles having to do with both hardware and physics. Certain microphones and recording devices have built-in features, for example, damping/normalizing that may be applied when the recording exceeds a threshold.