The objective of this project is to develop a real-time, low power, portable, underwater camera for mine detection based upon massively-parallel sonar processing techniques. The system will use either one two dimensional transducer of 1600 elements with a one inch aperature or a multiplicity of these transducers forming a synthetic aperature. At 10 metersa one transducer camera utilizing a 2MHz frequency will have a resolution of 11.6. This system can produce a 30 degree (36 lines in azimuth by 36 lines in elevation) 10 meter pyramidal scan in 1.3 seconds. Other scan formats are possible by trading off the angle of the scan with the frame rate. Resolution can be increased in both azimuth and elevation by arranging four such transducers 90 degrees apart around a circle to form a synthetic aperature. Such a camera that has an aperature of 12 would have a resolution of 1 at 10 meters. At 120 meters this camera would have a resolution of 12. Angle, range, and frame rate trade-offs are the same as for the one transducer camera. This work leverages off of the work that is being done to bring real-time ultrasound volumetric imaging for medical applications into reality. The medical imaging application is discussed below. When reading the work on medical imaging it should be kept in mind that the dynamic range considerations are much easier to dal with in water than in the human body, significantly simplifying the medical imaging systems electronics for the sonar application, even for much larger distances. This simiplification in turn will result in a much more compact, lower power implementation. 2D real-time phased array ultrasound has become a dominant medical imaging modality due to low costs, high efficacy and the absence of inonizing radiation. The total worldwide market for diagnostic ultrasound is $2 billion annually. Real-time phased array volumetric scanning systems (often called 4D Ultrasound Systems) promise an array of enhanced diagnostic capabilities, and will therefore replace 2D phased array ultrasound as the dominant ultrasound modality, especially incardiiology applications. 3D Ultrasound, Inc. owns the patent for the only known effective mechanism for implementing 3D real-time ultrasound images. I.e., receive mode parallel processing. 3D Ultrasound, Incl is just completing a commercial fully featured scalable real time phased array volumetric scanner. The basis for this machine will be the real time phased array volumetric scanner at Duke University
Keywords: real-time phased array massively parallel signal processing
