A demonstrator approach for the technology of a passive millimeterwave imaging system and the related image processing

A simple scanning system using linear drives with stepper motors in azimuth and transverse has been used to carry single channel millimeterwave radiometers at 35 GHz and 94 GHz. Dummies as well as humans carrying concealed objects under their clothing have been scanned to get information on the contrasts achievable outside and under indoor conditions. During the course of the experiments the scanning algorithms could be improved and new radiometers using low noise amplifiers with state of the art performance could be incorporated into the system. This resulted in a considerable acceleration of the necessary time to scan one human. In addition image enhancement methods have been developed to allow an automatic detection of concealed threat objects. The results achieved so far will allow to build a CWD system with real-time capability and improved image quality.