A new feature for the classification of echos of a transmitted signal based on the generalized target description is described, and a framework for adaptive classification using it is presented. The generalized target description is a parametric model for the target impulse response. The feature is an order parameter from this model, which can be computed empirically from the growth rate ofpower as a fimction of a scale for a certain wavelet transform ofthe echo. A set of acoustic backscatter data consisting ofretums from a mine and a rock with a linear FM transmit signal was analyzed. Parameters for the wavelet were computed from training sets so that this feature correctly distinguished 94% ofthe returns in test sets at 15 dB. The effectiveness ofthis feature as a classifier was found to degrade reasonably under increasing levels of synthetically generated reverberation noise. The simplest generalized target description model, a single order single center scatterer, was used. This model is not a realistic representation of the target impulse responses of either ofthe two objects, nevertheless it captured enough ofthe difference between the two to provide an effective classification tool.