Highly Accurate Target Motion Compensation Using Entropy Function Minimization

Authors: Amin Aghatabar Roodbary, Mohammad Hassan Bastani

Abstract:

One of the defects of stepped frequency radar systems is their sensitivity to target motion. In such systems, target motion causes range cell shift, false peaks, Signal to Noise Ratio (SNR) reduction and range profile spreading because of power spectrum interference of each range cell in adjacent range cells which induces distortion in High Resolution Range Profile (HRRP) and disrupt target recognition process. Thus Target Motion Parameters (TMPs) effects compensation should be employed. In this paper, such a method for estimating TMPs (velocity and acceleration) and consequently eliminating or suppressing the unwanted effects on HRRP based on entropy minimization has been proposed. This method is carried out in two major steps: in the first step, a discrete search method has been utilized over the whole acceleration-velocity lattice network, in a specific interval seeking to find a less-accurate minimum point of the entropy function. Then in the second step, a 1-D search over velocity is done in locus of the minimum for several constant acceleration lines, in order to enhance the accuracy of the minimum point found in the first step. The provided simulation results demonstrate the effectiveness of the proposed method.

Keywords: ATR, HRRP, motion compensation, SFW, TMP.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1474393

References:

[1] R. Zhang, X. Z. Wei and X. Li, ”The resolution of high resolution range profile for two ideal point targets,” 2012 IEEE International Conference on Information Science and Technology, Hubei, 2012, pp. 397-400.
[2] G. Sree Lakshmi, M. Sivasankar, S. Nandakumar ”Performance Analysis of High Resolution Range Profile,” 9th International Radar Symposium India, 2013.
[3] Hang-yong Chen, Yong-xiang Liu, Wei-dong Jiang and Gui-rong Guo, ”A new approach for synthesizing the range profile of moving targets via stepped-frequency waveforms,” in IEEE Geoscience and Remote Sensing Letters, vol. 3, no. 3, pp. 406-409, July 2006.
[4] E. Tilli and F. Prodi, ”Use of HRR data for target acceleration estimation: A simple but effective approach,” 2008 European Radar Conference, Amsterdam, 2008, pp. 224-227.
[5] K. T. Kim, ”Focusing of high range resolution profiles of moving targets using stepped frequency waveforms,” in IET Radar, Sonar and Navigation, vol. 4, no. 4, pp. 564-575, August 2010.
[6] B. Hu, L. Zhang, Z. Song and X. Zeng, ”Motion compensation for high range resolution profile based on stepped-frequency waveforms,” 2016 11th International Symposium on Antennas, Propagation and EM Theory (ISAPE), Guilin, 2016, pp. 850-853.
[7] H. R. Jeong, H. T. Kim and K. T. Kim, ”Application of Subarray Averaging and Entropy Minimization Algorithm to Stepped-Frequency ISAR Autofocus,” in IEEE Transactions on Antennas and Propagation, vol. 56, no. 4, pp. 1144-1154, April 2008.
[8] H. y. Chen, Y. x. Liu, X. Li and G. r. Guo, ”Mathematics of Synthesizing Range Profile,” in IEEE Transactions on Signal Processing, vol. 55, no. 5, pp. 1950-1955, May 2007.
[9] Wehner D. R.: High-resolution radar (Artech House,Norwood, MA, 1995).