R. Bhalla et H. Ling, A FAST ALGORITHM FOR SIGNATURE PREDICTION AND IMAGE-FORMATION USING THE SHOOTING AND BOUNCING RAY TECHNIQUE, IEEE transactions on antennas and propagation, 43(7), 1995, pp. 727-731
We present a fast simulation algorithm for generating the range profil
es and inverse synthetic aperture radar (ISAR) images of complex targe
ts using the shooting and bouncing ray (SBR) technique, Starting with
the time-domain and image-domain ray-tube integration formulas we deri
ved previously, we cast these formulas into a convolution form. The co
nvolution consists of a nonuniformly sampled signal and a closed-form
time-domain or image-domain ray spread function. Using a fast scheme p
roposed by Sullivan [1], the nonuniformly sampled function is first in
terpolated onto a uniform grid before the convolution is performed by
the fast Fourier transform (FFT) algorithm. Results for several comple
x targets are presented to demonstrate the tremendous computation time
savings and excellent fidelity of the scheme. Using the fast scheme,
a speed gain of a factor of 30 is achieved in performing the ray summa
tion as compared to the direct convolution in range profile computatio
n and a factor of 180 in ISAR image formation for a typical aircraft a
t X-band.