Multiple Scattering and microDoppler Effects in Radar Imaging and Target Recognition

Thursday, October 20, 2005 - 9:00am - 9:50am
EE/CS 3-180
Hao Ling (The University of Texas at Austin)
Synthetic aperture radar (SAR) and inverse synthetic
aperture radar (ISAR) systems have long been used by
the radar community for imaging air, sea and ground
targets. The standard radar imaging algorithms used
in these systems are based on the single-scattering,
point-scatterer model of the target. When the actual
target scattering is well approximated by this simple
model, the resulting high-resolution imagery reveals
useful geometrical features of the target for
classification and identification. However, sensor
data collected from real targets often contain higher
order effects. For instance, strong multiple
scattering can occur in a real target with reentrant
structures and inlet cavities. Further, a real target
being imaged by a radar sensor is often engaged in
dynamic maneuvers where the target does not remain a
rigid body. Some examples include the flexing and
vibration of the target frame and moving parts on the
target such as scanning antennas, moving wheels and
treads. These motions give rise to Doppler features
after the standard radar processing and have been
referred to as the microDoppler phenomenon. When
these higher order effects are present, the resulting
target imagery contains artifacts due to the mismatch
between the imaging model and the actual data. More
importantly, these features contain useful information
about the motion of the moving components and the
interior characteristics of the target, and should be
better exploited for target recognition. In this
talk, I will discuss our ongoing research in: (i) the
extraction, understanding and modeling of these
phenomena, and (ii) the exploitation of the resulting
models to achieve better imaging and recognition