2. The method of claim 1 , wherein the classifier is constructed using an expectation maximization (EM) method.
1. A method for unattended detection of a current terrain to be traversed by a mobile device, comprising the steps of: receiving, from a visual sensor, visual input of the current terrain for a plurality of positions; receiving audio input corresponding to the current terrain for the plurality of positions; fusing the video input with the audio input using a classifier; and classifying the type of the terrain with the classifier.