The US Army is replacing conventional armor with new types of ballistic protection which are lighter in weight than the materials they replace yet offer the same degree of protection. A key component of this new type of armor is called Multi Functional (MFA) or Sensor Enhanced Armor (SEA) because the armor provides more capabilities than traditional ballistic protection for the soldier and ground vehicle. In this paper we shall concentrate on the real-time health monitoring of SEA. We have developed a method which has been applied to several types of new ballistic protection. We use ultrasonic waves to excite the armor panel. We measure the response to the excitation when the ballistic protection is known to be undamaged and store the results in a database. To determine if the armor has been damaged, we measure it again and compare the new results to the contents of the database.