"Introducing a novel method for reducing coupling between range and angles in SIAR based on frequency coding in a circular array."

Document Type : Original Article

Authors

Department of Electrical Engineering, Malek-Ashtar University of Technology, Tehran, Iran.

Abstract

The Synthetic Impulse and Aperture Radar (SIAR) are radars that have characteristics such as the ability to detect low RCS targets, Low Probability Of Intercept , resistance to anti-radiation missiles, and simultaneous detection and tracking of multiple targets. In these radars, one of the most important challenges is coupling between range and angle. This means that range error causes angle error and vice versa. To address this issue, radar designers typically design transmitting waveforms based on carrier frequency coding techniques In the past, sequential carrier frequency coding, positive and the negative sequential carrier frequency coding and random carrier frequency coding have been proposed to reduce the coupling between range and angle for a linear array(2D). In this article, geometrical and mathematical equations of coupling are presented for a circular array(3D) and a new method called as positive and negative random carrier frequency coding is proposed. It will be shown that proposed method reduces coupling and side lobe level by about 40% more than the previous frequency coding methods. Moreover, we provide evidence that the coupling between azimuth and elevation angles remains consistent across different frequency coding techniques. Furthermore, the random change of carrier frequency coding from one transmit period to the next allows us to leverage pulse-to-pulse frequency agility, adding an additional advantage to this method

Keywords

Main Subjects


[1] Duofang, Chen, Ch. Baixiao, and Zh. "Multiple-input multiple-output radar and sparse array synthetic impulse and aperture radar." 2006 CIE international اجلاس on radar. IEEE, 2006.‏
[2] Chen, Baixiao, and J."Synthetic impulse and aperture radar (SIAR): a novel multi-frequency MIMO radar." John Wiley & Sons, 2014.‏              
[3] DOREY, Jacques, Y. BLANCHARD, and F. "Le projet RIAS, une approche nouvelle du radar de surveillance aérienne." Onde électrique 64.4 (1984): 15-20.
[4] Jianqi, Wu, et al. "Researches of a new kind of advanced meter wave radar." 2001 CIE International Conference on Radar Proceedings (Cat No. 01TH8559). IEEE, 2001.
[5] Chen, Baixiao, and Sh. "Performance analysis of pulse compression using phase-coded signals for sparse-array synthetic impulse and aperture radar." Journal of Electronics (China) 15 (1998): 332-338.
[6] Zhang, Q. W., Z. Bao, and Y. H. Zhang. "A novel method to from transmitting beam based on receiving array." Mod. Rad. 14.3 (1992): 41-51.
[7] Luce, A-S., et al. "Experimental results on RIAS digital beamforming radar." 92 International Conference on Radar. IET, 1992.
[8] Baixiao, Chen, L. Hongliang, and Zh. "Long-time coherent integration based on sparse-array synthetic impulse and aperture radar." 2001 CIE International Conference on Radar Proceedings (Cat No. 01TH8559). IEEE, 2001.
[9] Chen, Baixiao. "Researches on 4-Dimensional Tracking and Long-time Coherent Integration for Synthetic Impulse and Aperture Radar." Doctoral Dissertation (in Chinese) (1997).‏
[10] Chen, B., and S. Zhang. "4-Dimensional ambiguity function and resolution of sparse-array synthetic impulse and aperture radar." Signal Processing 44 (1998): 33-37.
[11] Zhao, GuangHui, GuangMing Shi, and JiaShe Zhou. "Angel estimation via frequency diversity of the SIAR radar based on Bayesian theory." Science China Technological Sciences 53 (2010): 2581-2588.
[12] Baixiao, Chen, et al. "Experimental system and experimental results for coast-ship Bi/multistatic ground-wave over-the-horizon radar." 2006 CIE International Conference on Radar. IEEE, 2006.
[13] Baixiao, Chen, et al. "Analysis and experimental results on sparse-array synthetic impulse and aperture radar." 2001 CIE International Conference on Radar Proceedings (Cat No. 01TH8559). IEEE, 2001.
[14] Wu, Jian-qi, and Jin Xu. "Some issues in the development of metric surveillance radar." 2013 International Conference on Radar. IEEE, 2013.
[15] Chen, Baixiao, et al. "The applications and future of synthetic impulse and aperture radar." 2016 CIE International Conference on Radar (RADAR). IEEE, 2016
[16] Zhengjian, Dai, Xu Jianping, and Zh. "The main practical performance of sparse-array synthetic impulse and aperture radar." 2009 IET International Radar Conference. IET, 2009.
[17] Chen, Baixiao, and Sh. "Study of frequency coding of transmitting signals for sparse-array synthetic impulse and aperture radar." ACTA Electronica Sinica 25 (1997): 64-68.‏
[18] Zhao, Yongbo, M. Liu, and Sh. "The grating lobe induced by the coupling of range and direction in siar and its elimination." 电子与信息学报23.4 (2001): 360-364.
[19] Zhang, Xue, et al. "A SIAR transmitting waveform design approach based on positive and negative sequential carrier frequency coding." IECON 2018-44th Annual Conference of the IEEE Industrial Electronics Society. IEEE, 2018.
[20] P. Yaghoubi, and H. "A New Method for SIAR Transmitting Waveforms to Reduce the Range-Angle Coupling." IEEE Sensors Letters 5.11 (2021): 1-4.