Studies of Quantitative Methods for Imaging from Scattered Fields
Rept. for 1 Feb-1 Oct 1989
LOWELL UNIV MA DEPT OF ELECTRICAL ENGINEERING
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The objective of this project remains reconstructing images from scattered field data. Concern is with targets or objects that cannot be considered weakly scattering, which makes the well known inversion schemes based on the first Born approximation of limited use. Methods based on distorted wave Born and Rytov approximations are under study, as well as techniques which treat the inversion procedure as a spectral estimation exercise. Owing to the difficulty in testing these new procedures with simulated data, due to the inherent difficulty in computing such data sets reliably, focus is on the use of real data from known simple targets. Work continues on the collection and interpretation of such scattered field data, which has been collected at the RADC Radar Cross Section Facility. Software has been developed to allow easy manipulation and display of these data sets as well as the images reconstructed from them. The capability exists for placing each scattered field data set on an arc of arbitrary radius and center in the Fourier domain and then interpolate these data to a cartesian grid this was important for the evaluation of one of the inversion methods under consideration. Display software has also been developed for further, to permit easy image manipulation on screen and hardcopy output onto an LN03 laser printer using binary fill patterns to represent grey scales. The numerical work is currently being carried out on VAX mainframes, via 2000 and 3100 workstations.
- Computer Programming and Software
- Active and Passive Radar Detection and Equipment