Angle Estimation of Unresolved Targets in Monopulse Radar via Creating Multiple Antenna Sets Using an Extra Antenna

Document Type : Original Article

Authors

1 Assistant Professor, Khatam Al Anbia Air Defense University, Tehran, Iran

2 Associate Professor, K.N. Toosi University, Tehran, Iran

3 Assistant Professor, Imam Hossein University, Tehran, Iran

4 Assistant Professor, Imam Hossein . University, Tehran, Iran

Abstract

Conventional monopulse radar cannot detect the direction of two closely-spaced targets in one resolution cell by utilizing the monopulse ratio. In this study, virtual amplitude-comparison monopulse signals are generated from the received phase-comparison monopulse signals, then a solution for estimation of the angles of two unresolved targets using a single snapshot of four independent channels is presented. If both targets have the same azimuth or elevation angle, the proposed scheme cannot detect their angles; an additional antenna is required, to detect such targets' angles. In this study, the antenna array is divided into multiple overlapping sets, to detect the direction of two targets at generalized positions in two different coordinates. Combining the outputs from multiple antenna sets improves the angle estimation performance and accuracy. The impact of SNR, the angle difference between the targets, and the phase difference of target signals on the accuracy of angle estimation have also been explained. The effectiveness of the proposed method is validated by comparing the exact solutions and simulations.

Keywords


Smiley face

[1]S.M. Sherman, D.K. Barton, “Monopulse Principles and Techniques (2nd ed.) ,” Boston, MA, Artech House, pp. 187–223, 2011.
[2] N. Gogineni, S. Nehorai, “Monopulse MIMO radar for target tracking,” IEEE Trans. Aerospace. Electron. System, 47, (1), pp. 755–768, 2011. DOI10.1109/TAES.2011.5705707
[3] Z. Wang, A. Sinha, P. Willett, “Angle estimation for two unresolved targets with monopulse radar,” IEEE Trans. Aerospace. Electron. System, 998 – 1019, 2004. DOI: 10.1109/TAES.2004.1337470
[5] M.J. Shi, J. Liu, “Improved two-targets resolution using dual-polarization radar with interlaced subarray partition,” IEEE International Conference on Electronic Measurement & Instruments, 397–400, China, 2017. DOI: 10.1109/ICEMI.2017.8265831
[7] S.P. Lee, B.L. Cho, S.M. Lee, “Unambiguous Angle Estimation of Unresolved Targets in Monopulse Radar,” IEEE Trans. Aerospace. Electron. System, VOL.51, NO. 2, 2015. DOI: 10.1109/TAES.2014.140178 
[8] J. Bosse, O. Rabaste, “Subspace rejection for matching pursuit in the presence of unresolved targets,” IEEE Transactions on Signal Processing, Vol. 66, No.8, 2018. DOI: 10.1109/TSP.2018.2795572
[10] Y.N. Zhao, Z.Q. Zhou, X.L. Qiao, “Angle estimation for two closely spaced targets with polarization monopulse radar,” Proceeding of 2005 Asia-Pacific Microwave Conference, 3– 8, Suzhou, China, 2005. DOI: 10.1109/APMC.2005.1606354
[12] Zh. Song, F. Cai, Q. Fu, “A Joint Detection and Tracking Algorithm for Unresolved Target and Radar Decoy,” Progress in Electromagnetics Research, Vol. 83, 43–60, 2019. DOI: 10.2528/PIERB18103101
[13] Zh. Lu, Y. Li, M. Gao, “Direction estimation for two steady targets in monopulse radar,” Journal of Systems Engineering and Electronics, February, Vol. 26, No. 1, pp.61–68, 2015. DOI: 10.1109/JSEE.2015.00009
[14] Zh.Y. Tseng, Yu K-B, “Closed-form four-channel monopulse two-target Resolution,” IEEE Trans. Aerospace. Electron. System, 39, 3, 1083—1089, 2003. DOI: 10.1109/TAES.2003.1238760
[15] Sh. Yufei, W. Jiazhi, M. Longfei, “Algorithm supplement of four-channel two-target resolution for amplitude-comparison monopulse radar,” Electronics Letters, Vol. 57 No. 17, 2021. DOI: 10.1049/ell2.12216
[16] W. Jianlu, X. Xiong, D. Huanya, S. Danhui, Q. Huidong, “Method for four-channel monopulse radar to resist dual-source angle deception jamming,” The Journal of Engineering IET, 2018. DOI:
[17] S. Jardak, S. Ahmed, M.S. Alouini, “Generalised two target localisation using passive monopulse radar,” IET Radar Sonar Navig, Vol. 11, pp. 932-936, 2017. DOI: 10.1049/iet-rsn.2016.0495
[18] S. Jardak, S. Ahmed, M.S. Alouini, “Two Target Localization Using Passive Monopulse Radar,” IEEE radar conference, 2015. DOI: 10.1109/RadarConf.2015.7411878
[19] S. L. Wang, Z.H. Xu, X. Yang, Zh. Li, G. Wang, “Efficient and Unambiguous Two-Target Resolution via Subarray-Based Four-Channel Monopulse,” IEEE Transactions on Signal Processing, VOL. 68, 2020. DOI: 10.1109/TSP.2020.2967184
[20] D.F. Crouse, “Comments on Closed-Form Four-Channel Monopulse Two-Target Resolution,” IEEE Trans. Aerospace. Electron. System, VOL. 48, NO.1, 2012. DOI: 10.1109/TAES.2012.6129678
[21] H. Rezaei. M.A. Sebt, N. Zarei, G. Saadati Moghadam, “Unambiguous Direction Estimation and Localization of Two Unresolved Targets via Monopulse Radar,” Electronics, 11(22), 3780, 2022. DOI: 10.3390/electronics11223780
[22] H. Rezaei. M.A. Sebt, N. Zarei, G. Saadati Moghadam, “Closed-form angle estimation of unresolved targets in monopulse radar to counter the angular electronic attack,” IET Signal Processing, 2023. DOI: 10.1049/sil2.12203
Volume 11, Issue 1
Serial number 29, spring and summer quarterly
August 2023
Pages 33-42
  • Receive Date: 25 March 2023
  • Revise Date: 30 June 2023
  • Accept Date: 29 July 2023
  • Publish Date: 24 August 2023