Analysis of radar detection of agitated metals (RADAM)

It has been observed that the radar returns from moving multielement metal targets often exhibit an unexpected modulation that has both random (or noise-like) and semicoherent components. One possible mechanism for producing this effect is the modification of the current distribution on the target that results when electrical contacts between target elements are altered intermittently by the forces associated with target motion. Such intermittent-contact modulation must be considered in the design of a radar for detecting or identifying a target exhibiting this effect. Depending on the application, the observer may wish to enhance or suppress the observation of the effect, or it may be important that the effect itself be enhanced or suppressed in the object being observed. To accomplish any of these, the effect must be well understood, and we have therefore undertaken a program of research to study the radar detection of agitated metals (RADAM). This report summarizes our progress during the second year of the program. The overall objectives of our RADAM research program are to (1) identify and isolate the physical processes and mechanisms that contribute to a RADAM signature, (2) identify and explain important recognizable features of the signature, and (3) determine means for separating the significant identifying components of the signature from nonmeaningful components.