Abstract: A method and system of imaging at least one passive object within a surrounding structure is provided. The surrounding structure has multiple surfaces. The method includes: transmitting an ultrasonic signal into the surrounding structure using an array of ultrasonic transmitters and receiving reflections from the passive object using an array of ultrasonic receivers. The method also includes steering the ultrasonic signal such that it includes at least one reflection off a surrounding structure surface using stored data relating to a position of at least one of the surfaces.