System and method for detecting and aligning acoustic beam in situ to a target using wide-beam, low frequency (<1 mhz) ultrasound

A method for locating a target in situ, comprising the steps of:

• emitting pulses of ultrasonic energy waves having one or more frequencies ranging from 100 kHz to 1 MHz by an excitation transducer, wherein an average wavelength of said ultrasonic energy waves is greater than a size of the target,
• wherein said ultrasonic energy waves are approximately collimated in a volume away from an aperture;
• and
• receiving, by a sensing transducer, a component of the pulses of the ultrasonic energy waves emitted by said excitation transducer after reflection from the target,
• wherein said component of the pulses of the ultrasonic energy waves has an average wavelength greater than the size of the target and is related to a position of the target.