Share Email Print
cover

Proceedings Paper

Refocusing vibrating targets in SAR images
Author(s): Qi Wang; Balu Santhanam; Matthew Pepin; Tom Atwood; Majeed M. Hayat
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

In synthetic-aperture radar (SAR) returned signals, ground-target vibrations introduce a phase modulation that is linearly proportional to the vibration displacement. Such modulation, termed the micro-Doppler effect, introduces ghost targets along the azimuth direction in reconstructed SAR images that prevents SAR from forming focused images of the vibrating targets. Recently, a discrete fractional Fourier transform (DFrFT) based method was developed to estimate the vibration frequencies and instantaneous vibration accelerations of the vibrating targets from SAR returned signals. In this paper, a demodulation-based algorithm is proposed to reconstruct focused SAR images of vibrating targets by exploiting the estimation results of the DFrFT-based vibration estimation method. For a single-component harmonic vibration, the history of the vibration displacement is first estimated from the estimated vibration frequency and the instantaneous vibration accelerations. Then a reference signal whose phase is modulated by the estimated vibration displacement with a delay of 180 degree is constructed. After that, the SAR phase history from the vibration target is multiplied by the reference signal and the vibration-induced phase modulation is canceled. Finally, the SAR image containing the re-focused vibration target is obtained by applying the 2-D Fourier transform to the demodulated SAR phase history. This algorithm is applied to simulated SAR data and successfully reconstructs the SAR image containing the re-focused vibrating target.

Paper Details

Date Published: 4 May 2012
PDF: 8 pages
Proc. SPIE 8361, Radar Sensor Technology XVI, 836106 (4 May 2012); doi: 10.1117/12.919521
Show Author Affiliations
Qi Wang, The Univ. of New Mexico (United States)
Ctr. for High Technology Materials, Univ. of New Mexico (United States)
Balu Santhanam, The Univ. of New Mexico (United States)
Matthew Pepin, The Univ. of New Mexico (United States)
Ctr. for High Technology Materials, Univ. of New Mexico (United States)
Tom Atwood, Sandia National Labs. (United States)
Majeed M. Hayat, The Univ. of New Mexico (United States)
Ctr. for High Technology Materials, Univ. of New Mexico (United States)


Published in SPIE Proceedings Vol. 8361:
Radar Sensor Technology XVI
Kenneth I. Ranney; Armin W. Doerry, Editor(s)

© SPIE. Terms of Use
Back to Top