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Covariance Matrix Estimation with Small STAP Data through Conversion into Spatial Frequency-Doppler Plane

적은 STAP 데이터의 공간주파수-도플러 평면 변환을 이용한 공분산행렬 추정

  • Hoon-Gee Yang (Dept. of Electronic Convergence Engineering, Kwangwoon University)
  • Received : 2023.02.09
  • Accepted : 2023.02.24
  • Published : 2023.03.31

Abstract

Performance of a STAP(space-time adaptive processing) algorithm highly depends on how closely the estimated covariance matrix(CM) resembles the actual CM by the interference in CUT(cell under test). A STAP has 2 dimensional data structure determined by the number of array elements and the number of transmitting pulses and both numbers are generally not small. Thus, to meet the degree of freedom(DOF) of the CM, a huge amount of training data is required. This paper presents an algorithm to generate virtual training data from small received data, via converting them into the data in spatial frequency-Doppler plane. We theoretically derive where the clutter exist in the plane and present the procedure to implement the proposed algorithm. Finally, with the simulated scenario of small received data, we show the proposed algorithm can improve STAP performance.

STAP(space-time adaptive processing) 알고리즘의 성능은 CUT(cell under test) 내의 간섭에 대한 공분산 행렬 추정의 정확도가 결정적 역할을 한다. STAP 데이터는 일반적으로 많은 배열 소자 및 사용된 다수의 송신 펄스에 의해 결정되는 2차원 데이터 구조를 가지고 있다. 그러므로 공분산 행렬 추정의 정확도를 높이기 위해서는 매우 많은 트레이닝 데이터가 요구된다. 본 논문에서는 수신된 적은 개수의 데이터를 공간주파수-도플러 평면으로 변환한 후 가상의 트레이닝 데이터를 생성하는 알고리즘을 제시한다. 클러터 점유 위치를 이론적으로 유도하며 이에 근거해서 가상 트레이닝 데이터 생성 절차를 제시하고 STAP 시뮬레이션을 통해서 제시된 알고리즘이 STAP 성능을 개선할 수 있음을 보인다.

Keywords

Acknowledgement

The present research has been conducted by the Excellent researcher support project of Kwangwoon University in 2021.

References

  1. Klemm, R., Space-Time Adaptive Processing: Principles and Applications, London, England: IEEE Press, 1998.
  2. Guerci, J. R., Space-Time Adaptive Processing for radar, Artech House, 2003.
  3. M. Liu, L. Zou, X. Yu, Y. Zhou, X. Wang, and B. Tang, "Knowledge Aided Covariance Matrix Estimation via Gaussian Kernel Function for Airborne SR-STAP," IEEE Access, vol.8, pp.5970-5978, 2020. DOI: 10.1109/ACCESS.2020.2963838
  4. K. Duan, H. Yuan, and H. Xu, "Sparsitybased non-stationary clutter suppression technique for airborne radar," IEEE Access, vol.6, pp. 56162-56169, 2018. DOI: 10.1109/ACCESS.2018.2873021
  5. S. Sen, "OFDM radar spacetime adaptive processing by exploiting Spatiotemporal sparsity," IEEE Trans. Signal Process., vol.61, no.1, pp.118-130, 2013. DOI: 10.1109/TSP.2012.2222387
  6. X. Yang, Y. Liu, and T. Long, "Robust nonhomogeneity detection algorithm based on prolate spheroidal wave functions for space-time adaptive processing," IET Radar, Sonar Navigat., vol.7, no.1, pp.47-54, 2013. DOI: 10.1049/iet-rsn.2011.0404
  7. Y. Gao, H. Li, and B. Himed, "Knowledgeaided range-spread target detection for distributed MIMO radar in nonhomogeneous environments," IEEE Trans. Signal Process., vol.65, no.3, pp.617-627, 2017. DOI: 10.1109/TSP.2016.2625266
  8. S. Zhang, Z. He, J. Li, and Y. Wang, "A robust colored-loading factor optimization approach for knowledge-aided STAP," in Proc. IEEE Radar Conf., pp.1-5, 2016. DOI: 10.1109/RADAR.2016.7485266
  9. Y. Wang and Z. He, "Thinned knowledgeaided STAP by exploiting structural covariance matrix," IET Radar, Sonar Navigat., vol.11, no.8, pp.1266-1275, 2017. https://doi.org/10.1049/iet-rsn.2017.0060
  10. R. S. Raghavan, "CFAR detection in clutter with a Kronecker covariance structure," IEEE Trans. Aerosp. Electron. Syst., vol.53, no.2, pp. 619-629, 2017. DOI: 10.1109/TAES.2017.2651599
  11. X. Zhang, Q. Yang, and W. Deng, "Weak target detection within the nonhomogeneous ionospheric clutter background of HFSWR based on STAP," Int. J. Antennas Propag., vol.2013, 2013. DOI: 10.1155/2013/382516
  12. Y. Wu, T. Wang, J. Wu, and J. Duan, "Training sample selection for space-time adaptive processing in heterogeneous environ-ments," IEEE Geosci. Remote Sens. Lett., vol.12, no.4, pp.691-695, 2015. DOI: 10.1109/LGRS.2014.2357804
  13. H. Li, W. Bao, J. Hu, J. Xie, and R. Liu, "A training samples selection method based on system identification for STAP," Signal Process., vol.142, pp.119-124, 2018. DOI: 10.1016/j.sigpro.2017.07.008