In this paper, a method to obtain 3-dimensional Computer-Aided Design (CAD) models of radar targets from their real shapes is proposed for the construction of a database which is composed of scattering centers of the targets and a consideration of an efficient formation of the database from the appropriate collection of Radar Cross Section (RCS) data is also described. As 3-dimensional CAD models of the targets are not available in many cases, a method to make a geometric model from the real target is needed. Three dimensional coordinates of the target can be measured by a laser scanner. These measured coordinates are combined to form a 3D CAD model of the target. With the CAD model obtained, RCS values of the target are calculated over a series of frequencies and angle apertures to be transformed into scattering centers by a superresolution technique, which is Matrix Pencil (MP) in this case. The CAD model of an air-target is utilized for the test to infer the criterion on the frequency of the sets of extracted scattering centers for the optimal database construction, where RCS data sets are calculated every 5, 10, 15 and 20 degrees in azimuth direction to be used for the scattering center extraction. And then, RCS values are reconstructed from those sets of scattering centers to compare with the original RCS values of the target to determine how many sets of scattering centers our database should have over the whole azimuth angles. The result show that the smaller the angle gap between the adjacent sets of scattering centers, the better match between the original RCS and the reconstructed RCS.
