Vc. Chen et S. Qian, JOINT TIME-FREQUENCY TRANSFORM FOR RADAR RANGE DOPPLER IMAGING, IEEE transactions on aerospace and electronic systems, 34(2), 1998, pp. 486-499
Conventional radar imaging uses the Fourier transform to retrieve Dopp
ler information. However, due to the complex motion of a target, the D
oppler frequency shifts are actually time-varying. By using the Fourie
r transform, the Doppler spectrum becomes smeared and the image is blu
rred. Without resorting to sophisticated motion compensation algorithm
s, the image blurring problem can be resolved with the joint time-freq
uency transform. High-resolution time-frequency transforms are investi
gated, and examples of applications to radar imaging of single and mul
tiple targets with complex motion are given.