Applying Fractional Fourier Transform to Two-Aperture SAR-GMTI


  1. Chiu, S.
  2. Sikameta, I.
Corporate Authors
Defence R&D Canada - Ottawa, Ottawa ONT (CAN)
SAR along-track interferometry (SAR-ATI) can be used to measure motion in a scene by utilizing the phase and magnitude information of the interferogram. The phase of a target's interferogram delta Ø is, to first order, proportional to as slant range velocity vr, at broadside. Due to the nature of SAR data collection, the moving target signal is unavoidably contaminated by the scene clutter. Depending on the signal-to-clutter ratio (SCR), the velocity and the azimuth shift estimated from the phase may have significant errors. The proposed technique applies the so-called fractional Fourier transform (FrFT) to improve the SCR in order to reduce the clutter contamination effect on the interferometric phase. By mapping a target's signal onto a fractional Fourier axis, its energy can be highly compressed, at same time filtering out most of the interfering clutter. Two-channel airborne SAR data were used for this study. Results show that the proposed method is an effective and elegant way of accurately estimating velocity and position parameters.
Report Number
DRDC-OTTAWA-SL-2004-032 — Scientific Literature
Date of publication
30 May 2004
Number of Pages
Reprinted from
Proceedings EUSAR, 2004, p 819-822
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