Microwave radar imaging of rotating blades

Microwave radar imaging of rotating blades is investigated. A significant component of the signal energy arises from the blade flashes and this can be detected and extracted from the time-domain data to form an image. The method proposed for achieving this is based upon the use of a signal model corresponding to the structural components of a blade, a form of the matched filter, a `matching pursuit´ representation, and a form of the CLEAN technique. From this an image of a rotating blade can be synthesised, while the coefficients in the matching pursuit representation may be used for effective target classification. In this paper we demonstrate the techniques on data collected from rotating helicopter blades.