Wu Jie

Publications (2)0 Total impact

• Conference Proceeding: A new motion compensation method for ISAR based on time-frequency analysis and image processing

  Wu Jie, Zhang Yun-hua
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  ABSTRACT: In this paper, a new motion compensation approach for inverse synthetic aperture radar (ISAR) is proposed based on time-frequency analysis and image processing to the time-frequency image. In the approach, the velocity estimation is obtained by traditional curve-fitting technique, but the acceleration estimation is obtained by image-processing technique and curve-fitting technique together. Image-processing technique is used to get the time-frequency distribution of a chosen range cell after initial velocity compensation, and curve-fitting technique is used again to get the slope, which is proportional to acceleration. Computer simulation shows the accuracy of the estimated motion parameters by the new approach is satisfied for ISAR imaging, although the simplest time-frequency analysis method, i.e. short time frequency transform (STFT) is used. At the same time, the method is very competitive in speed with others for real-time processing of ISAR data.
  Microwave Conference Proceedings, 2005. APMC 2005. Asia-Pacific Conference Proceedings; 01/2006
• Conference Proceeding: Sidelobes and grating lobes reduction of stepped-frequency chirp signal

  Li Hai-bin, Zhang Yun-hua, Wu Jie
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  ABSTRACT: This paper studies several methods for decreasing both sidelobes and grating lobes of FJB signal by using linear windowing, nonlinear windowing, and nonlinear stepping. We apply SVA (spatial variant apodization) as nonlinear windowing to lower down the lobes, and at the same time, keep the mainlobe unchanged. Study shows that apply SVA on single pulse of FJB burst does not help, but apply SVA on the whole FJB burst help to suppress sidelobes significantly. If we apply Hanning windowing on single pulse and SVA on the whole burst, both sidelobes and grating lobes can be suppressed significantly. At the same time, the mainlobe almost kept unchanged. At last, we propose a new nonlinear model, i.e. a tangent-function model for choosing the frequency steps in a FJB burst. This nonlinear FJB signal (NFJB) has been shown to be of much better performance than conventional linear FJB signal does. Simulation shows that if apply Hanning windowing on each single pulse in NFJB, the grating lobes can be lowered down more significantly.
  Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, 2005. MAPE 2005. IEEE International Symposium on; 09/2005