High-speed fragment tracking with sparse frames using space–time interlaced X-ray imaging

Explosively driven fragments were tracked in three spatial dimensions and time using a proposed space–time interlaced X-ray tracking method. When a limited number of frames are available and linear trajectories can be assumed (over four timesteps), three-dimensional paths can be determined by fitting a unique line that intersects the possible fragment centers of mass. These possible locations are determined by back projecting density information from the images collected by temporally and spatially (angular) interlaced views of fragments in the region of interest. Furthermore, the use of penetrating radiation overcomes optical interferences in the near field and enables direct measurement of fragments mass. Experimental results are presented to quantify the capabilities and limitations of the imaging methodology. Measurement uncertainties and methodology biases are addressed and discussed.