Ultrasonic-based system for detection of metallic security threats containers on cargo

A system for imaging objects on a surface, the system comprising:

• an ultrasonic transmitter having an ultrasonic transducer in contact with a surface configured to excite the surface with ultrasonic excitation;
• an ultrasonic receiver in contact with the surface configured to receive ultrasonic reflections of the ultrasonic excitation;
• a motion module configured to move (i) the surface or the ultrasonic transmitter and the ultrasonic receiver such that the surface moves relative to the ultrasonic transmitter and the ultrasonic receiver or (ii) the ultrasonic transmitter and the ultrasonic receiver such that the ultrasonic transmitter and the ultrasonic receiver move relative to the surface;
• a processor;
• and
• a memory with computer code instructions stored therein, the memory operatively coupled to said processor such that the computer code instructions configure the processor to implement an imaging module configured to image a two-dimensional representation of the object acoustically coupled to the surface based on the received ultrasonic reflections.