Abstract—Inthispaper,wefacetheproblemofconstructingarobustfeaturespaceforautomaticclassificationofsignalsfromnarrow-bandin-airultrasonicsensors.Inconsiderationoftheexistingsensorbandwidthrestrictions,theimportanceofselectingasuitablesignaldescriptorishighlighted.Weassumethatthecharacterist