1. A method of determining whether a biometric object is part of a live individual, comprising: acquiring image information from the biometric object using an ultrasonic sensor, wherein acquiring the image information involves a plurality of range gate delays and a plurality of ultrasonic frequencies; and analyzing the image information in at least two analysis stages, wherein one of the analysis stages is a temporal analysis stage that analyzes changes in the image information obtained during a time period throughout which the biometric object was continuously available to the sensor and the other of the analysis stages involves analyzing the image information to determine whether the biometric object includes at least one manufactured layer.