Journal of the Korean Society for Aeronautical & Space Sciences (한국항공우주학회지)

The Korean Society for Aeronautical and Space Sciences (한국항공우주학회)
권호 표지
DOI QR코드

DOI QR Code

Motion Sensing Algorithm for SAR Image Using Pre-Parametric Error Modeling

매개변수 사전 오차 모델링 기법을 이용한 SAR 요동측정 알고리즘

  • Park, Woo Jung (Department of Mechanical and Aerospace Engineering/Automation and System Research Institute, Seoul National University) ;
  • Park, Yong-gonjong (Department of Mechanical and Aerospace Engineering/Automation and System Research Institute, Seoul National University) ;
  • Lee, Soojeong (Department of Mechanical and Aerospace Engineering/Automation and System Research Institute, Seoul National University) ;
  • Park, Chan Gook (Department of Mechanical and Aerospace Engineering/Automation and System Research Institute, Seoul National University) ;
  • Song, Jong-Hwa (Avionics Radar Team, Hanwha Systems) ;
  • Bae, Chang Sik (Avionics Radar Team, Hanwha Systems)
  • Received : 2019.05.23
  • Accepted : 2019.07.27
  • Published : 2019.08.01
Download PDF
⟨ Previous Next ⟩

Abstract

In order to obtain high-quality images by motion compensation in the airborne synthetic aperture radar (SAR), accurate motion sensing in image acquisition section is necessary. Especially, reducing relative position error and discontinuity in motion sensing is important. To overcome the problem, we propose a pre-parametric error modeling (P-PEM) algorithm which is a real-time motion sensing algorithm for the airborne SAR in this paper. P-PEM is an extended version of parametric error modeling (PEM) method which is a motion sensing algorithm to mitigate the errors in the previous work. PEM estimates polynomial coefficients of INS error which can be assumed as a polynomial in the short term. Otherwise, P-PEM estimates polynomial coefficients in advance and uses at image acquisition section. Simulation results show that the P-PEM reduces relative position error and discontinuity effectively in real-time.

항공 SAR에서 고품질의 영상을 얻기 위해서는 영상 획득 구간에서 항공기의 요동을 정확히 측정하여야 한다. 특히 요동측정을 할 때 상대적 위치오차 및 불연속성 오차를 줄여야 한다. 이를 해결하기 위해 본 논문에서는 합성 개구 레이더(SAR)에서 실시간으로 요동측정을 하는 매개변수 사전 오차 모델링 방법(P-PEM, Pre-Parametric Error Modeling)을 제안한다. P-PEM은 기존에 본 연구진에서 제안한 항법오차를 다항식으로 모델링하여 추정하는 매개변수 오차 모델링 기법(PEM, Parametric Error Modeling)에서 확장된 기법이다. PEM은 IMU에 의한 INS 오차를 짧은 시간 동안 다항식이라 가정하여 모델링하는 요동측정기법이다. 반면, P-PEM은 다항식 오차 모델의 계수를 미리 추정하고 영상촬영단계에서 사용한다. 시뮬레이션 결과, P-PEM을 적용하면 실시간으로 불연속성 오차를 제거한 요동측정이 가능함을 확인하였다.

Keywords

References

  1. Moreira, A., Prats-Iraola, P., Younis, M., Krieger, G., Hajnsek, I., and Papathanassiou, K. P., "A Tutorial on Synthetic Aperture Radar," IEEE Transactions on Geoscience and Remote Sensing, Vol. 1, No. 1, 2013, pp. 6-43.
  2. Cheney, M., and Borden, B., "Fundamentals of Radar Imaging," Philadelphia, USA: Siam, 2009.
  3. Moreira, A., and Huang, Y., "Chirp Scaling Algorithm for Processing SAR Data with High Squint Angle and Motion Error," SAR Data Processing for Remote Sensing, Vol. 2316, 1994, pp. 268-278. https://doi.org/10.1117/12.197547
  4. Haslam, G. E., and Damini, A., "Specifying the Allowable Latencies in the Application of SAR Motion Corrections," Proceedings of EUSAR '96, European Conference on Synthetic aperture radar, 1996, pp. 26-28.
  5. Kim, T. J., "Motion Measurement for High-accuracy Real-time Airborne SAR," Radar Sensor Technology VIII and Passive Millimeter-Wave Imaging Technology VII, 2004, pp. 36-45.
  6. Doerry, A. W., "Motion Measurement for Synthetic Aperture Radar," Sandia National Laboratories Report SAND2015-20818, 2015.
  7. Kim, T. J., Fellerhoff, J. R., and Kohler S. M., "An Integrated Navigation System Using GPS Carrier Phase for Real-Time Airborne/Synthetic Aperture Radar (SAR)," Navigation, Vol. 48, No. 1, 2001, pp. 13-24. https://doi.org/10.1002/j.2161-4296.2001.tb00224.x
  8. Kusk, A., Dall, J., and Christensen, E. L., "Estimating Sensor Motion in Airborne SAR(Ph.D. dissertation)," Technical University of Denmark, Copenhagen, Denmark, 2006.
  9. Mao, Y., Xiang, M., Wei, L., and Han, S., "The Effect of IMU Inaccuracies on Airborne SAR imaging," Journal of Electronics (China), Vol. 28, 2011, pp. 409-418. https://doi.org/10.1007/s11767-012-0617-1
  10. Buckreuss, S., "Motion Errors in an Airborne Synthetic Aperture Radar System," European Transactions on Telecommunications, Vol. 2, No. 6, 1991, pp. 655-664. https://doi.org/10.1002/ett.4460020609
  11. Fang, J., and Gong, X., "Predictive Iterated Kalman Filter for INS/GPS Integration and Its Application to SAR Motion Compensation," IEEE Transactions on Instrumentation and Measurement, Vol. 59, No. 4, 2010, pp. 909-915. https://doi.org/10.1109/TIM.2009.2026614
  12. Song, J. W., and Park, C. G., "INS/GPS Integrated Smoothing Algorithm for Synthetic Aperture Radar Motion Compensation Using an Extended Kalman Filter with a Position Damping Loop," International Journal of Aeronautical and Space Sciences, Vol. 18, No. 1, 2017, pp. 118-128. https://doi.org/10.5139/IJASS.2017.18.1.118
  13. Xing, M., Jiang, X., Wu, R., Zhou, F., and Bao, Z., "Motion Compensation for UAV SAR Based on Raw Radar Data," IEEE Transactions on Geoscience and Remote Sensing, Vol. 47, No. 8, 2009, pp. 2870-2883. https://doi.org/10.1109/TGRS.2009.2015657
  14. Zhang, L., Wang, G., Qiao, Z., and Wang, H., "Azimuth Motion Compensation with Improved Subaperture Algorithm for Airborne SAR Imaging," IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, Vol. 10, No. 1, 2016, pp. 184-193. https://doi.org/10.1109/JSTARS.2016.2577588
  15. Park, Y., and Park, C. G., "Kalman Smoother Based Mitigation Method of Relative Position Error for Precision Improvement of Aviation SAR," Proceeding of The Korean Society for Aeronautical and Space Sciences Spring Conference, 2016, pp. 558-559.
  16. Park, Y., Park, Y. B., Jung, J., Shin, H. S., and Park, C. G., "Novel Motion Sensing Algorithm for Improving SAR Imaging by Parametric Error Modeling," International Journal of Aeronautical and Space Sciences, 2019, pp. 1-7.
  17. Titterton, D. H., and Weston, J. L., "Strapdown Inertial Navigation Technology(2nd edition)," The Institution of Electrical Engineers, Stevenage, UK, 2004.