Disclosed is a fully automated system capable of producing high quality real-time S-parameter images. It is a useful and versatile tool in Material Science and Solid State Technology for determining the location of subsurface defect types and concentrations in bulk-materials as well as thin-films. The system is also useful in locating top surface metallizations and structures in solid state devices. This imaging system operates by scanning the sample surface with either a small positron source (.sup.22Na) or a focused positron beam. The system also possesses another two major parts, namely electronic instrumentation and stand-alone imaging software. In the system, the processing time and use of system resources are constantly monitored and optimized for producing high resolution S-parameter image of the sample in real time with a general purpose personal computer. The system software possesses special features with its embedded specialized algorithms and techniques that provide the user with adequate freedom for analyzing various aspects of the image in order to obtain a clear inference of the defect profile while at the same time keeping automatic track on the instrumentation and hardware settings. The system is useful for semiconductor and metal samples, giving excellent quality images of the subsurface defect profile and has applications for biological samples.