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Huzme Demet Filtresi kullanılarak Yakın Alan YT-SAR Görüntü Kalitesinin İyileştirilmesi

Year 2020, Ejosat Special Issue 2020 (ICCEES), 480 - 487, 05.10.2020
https://doi.org/10.31590/ejosat.820286

Abstract

Bu çalışmada, yakın-alan yer tabanlı sentetik açıklıklı radar (GB-SAR) görüntülemede kullanılan geri projeksiyon algoritmasından (BPA) kaynaklanan görüntü gürültüsünü ve karmaşayı ortadan kaldırmak için anten ışın genişliği filtresi kullanılmıştır. BPA her bir sentetik açıklıkta elde edilen menzil profilini, görüntülenecek bölge üzerine interpole ettiği için, antenin huzme genişliği içinde toplanan saçılımları tüm bölgeye yaymakta ve bunun sonucu odaklanmış görüntüde gürültü oluşmaktadır. Çalışmada sunulan basit ama etkili teknik sayesinde, her bir menzil profili sadece anten ışın demetinin karşılık geldiği bölgeye yayılarak gürültüsüz ve oldukça temiz bir radar görüntüsü elde edilmiştir. Anten ışın demet filtresinin etkinliği öncelikle benzetim sonuçları ile doğrulanmış ardından 2 farklı gerçek deney gerçekleştirilmiştir. Hem benzetim deneyleri hemde gerçek ölçümler, adım frekans sürekli dalga radar formu ile gerçekleştirilmiştir. Birinci deneyde sentetik açıklık göreceli olarak kısa olduğu ve hedeflenen bölgede metal yansıtıcı dışında herhangi bir baskın yansıtıcı bulunmadığı için, geleneksel BPA sonucu ile filtreli BPA sonuçları arasında çok yüksek görüntü bozulmaları meydana gelmemiştir. Buna rağmen hedefin odaklanmasında görsel olarak farkedilir bozulmalar oluşmuş ve görüntülenen sahnede gürültü işaretleri ortaya çıkmışıtır. İkinci deneyde nisbeten uzun bir mesafede tarama yapıldığı ve taranan bölgede çok fazla saçıcı bulunması nedeniyle, filtreli ve filtresiz BPA sonuçları arasında oldukça dikkate değer farklar gözlemlenmiştir. Filtreli BPA sonucu elde edilen görüntüde tüm hedeflerin yüksek çözünürlüklü ve yüksek kontrastla odaklanırken, filtresiz BPA sonucu elde edilen görüntüde bazı küçük hedeflerin gürültüde kaybolduğu gözlemlenmiştir. Tüm bu çalışmalar sonucu, ışın demet filtreli BPA’nın oldukça yüksek performansa ve görüntü kalitesine sahip olduğu ortaya konulmuştur.

References

  • Yigit E, Demirci S, Ozdemir C, Tekbas M. Short-range ground-based synthetic aperture radar imaging: performance comparison between frequency-wavenumber migration and back-projection algorithms. J. Appl. Remote Sensing. 2013;7(1): 073483 – 073483.
  • M. Pieraccini, G. Luzi, D. Mecatti, L. Noferini and C. Atzeni, “ Ground-based SAR for short and long term monitoring of unstable slopes ” Proceedings of the 3rd European Radar Conference, 92- 95 (2006).
  • Yigit E, Demirci S, Unal A, Ozdemir C, Vertiy A. Millimeter-wave ground-based synthetic aperture radar imaging for foreign object debris detection: experimental studies at short ranges. J. Infrared Millimeter Terahertz Waves. 2012;33(12):1227 – 1238.
  • S.P Beasly, G. Binns, R. Hodges, R.J Badley, Tarsier., “ A Millimetre Wave Radar for Airport Runway Debris Detection ” , in Proc. of EURAD ’ 04, Amsterdam (2004).
  • Yigit E, Unal A, Demrici S, Vertiy A, Ozdemir C. An adapted mathced filter algorithm for millimeter wave ground based squint mode SAR applications, 2011 International Conference on Infrared, Millimeter, and Terahertz Waves, DOI: 10.1109/irmmw-THz.2011.6105117.
  • Demirci S, Çetinkaya H, Yigit E,Ozdemir C, Vertiy A. A Study on Mıllımeter-Wave Imagıng Of Concealed Objects: Applıcatıon Usıng Back-Projectıon Algorıthm, Progress In Electromagnetics Research, Vol. 128, 457–477, 2012.
  • Yigit E, Demrici S, Ozdemir C, Kavak A. A Synthetıc Aperture Radar-Based Focusıng Algorıthm For B-Scan Ground Penetratıng Radar Imagery, Mıcrowave And Optıcal Technology Letters / Vol. 49, No. 10, 2007.
  • Yigit E. Construction of synthetic aperture radar system for ground platforms and obtaining real terrestrial radar images, Phd. Thesis, Mersin University, Institute of Science. 2013.
  • Mersereau R, Oppenheim “A. Digital reconstruction of multidimensional signals from their projections”. P IEEE, 62(10): 1319–38, (1974).
  • Demirci S. Yigit E. Eskidemir I.H, Ozdemir C. Ground penetrating radar imaging of water leaks from buried pipes based on back-projection method, NDT&E International 47 (2012) 35–42.

Enhancement of Near Field GB-SAR Image Quality Using Beamwidth Filter

Year 2020, Ejosat Special Issue 2020 (ICCEES), 480 - 487, 05.10.2020
https://doi.org/10.31590/ejosat.820286

Abstract

In this study, the antenna beamwidth filter (ABF) was used to eliminate the image noise and clutter originating from the back-projection algorithm (BPA) used in near field ground-based synthetic aperture radar (GB-SAR) imaging. Since BPA interpolates the range profile obtained in each synthetic aperture onto the region to be imaged, it spreads the scattering collected in the beamwidth of the antenna to the whole region and as a result, noise occurs in the focused image. Thanks to the simple but effective technique presented in the study, each range profile was spread only to the area where the antenna beam corresponds to, and a noise-free and very clean radar images have been obtained. The effectiveness of the ABF was first verified with the simulation data and then two different real experiments were carried out. Both simulation and real measurements were carried out with step frequency continuous wave radar form. In the first experiment, because the synthetic aperture was relatively short and there was no dominant scatterer other than a metal reflector in the scene, very high image distortions did not occur between the traditional BPA and the filtered BPA results. Dispite these results, there were visually noticeable distortions that occurred in the focusing of the target and noisy signs appeared in the imaged scene. In the second experiment, quite notable differences were observed between filtered and traditional BPA results, as the scan was performed over a relatively long distance and there were too many scatterers in the target area. In the image reconsctructed using filtered BPA, while all targets were focused with high resolution and high contrast, in the image obtained by traditional BPA, it was observed that some small targets disappear under the noise signs. As a result of all these findings, it has been revealed that BPA with ABF has quite high performance and image quality.

References

  • Yigit E, Demirci S, Ozdemir C, Tekbas M. Short-range ground-based synthetic aperture radar imaging: performance comparison between frequency-wavenumber migration and back-projection algorithms. J. Appl. Remote Sensing. 2013;7(1): 073483 – 073483.
  • M. Pieraccini, G. Luzi, D. Mecatti, L. Noferini and C. Atzeni, “ Ground-based SAR for short and long term monitoring of unstable slopes ” Proceedings of the 3rd European Radar Conference, 92- 95 (2006).
  • Yigit E, Demirci S, Unal A, Ozdemir C, Vertiy A. Millimeter-wave ground-based synthetic aperture radar imaging for foreign object debris detection: experimental studies at short ranges. J. Infrared Millimeter Terahertz Waves. 2012;33(12):1227 – 1238.
  • S.P Beasly, G. Binns, R. Hodges, R.J Badley, Tarsier., “ A Millimetre Wave Radar for Airport Runway Debris Detection ” , in Proc. of EURAD ’ 04, Amsterdam (2004).
  • Yigit E, Unal A, Demrici S, Vertiy A, Ozdemir C. An adapted mathced filter algorithm for millimeter wave ground based squint mode SAR applications, 2011 International Conference on Infrared, Millimeter, and Terahertz Waves, DOI: 10.1109/irmmw-THz.2011.6105117.
  • Demirci S, Çetinkaya H, Yigit E,Ozdemir C, Vertiy A. A Study on Mıllımeter-Wave Imagıng Of Concealed Objects: Applıcatıon Usıng Back-Projectıon Algorıthm, Progress In Electromagnetics Research, Vol. 128, 457–477, 2012.
  • Yigit E, Demrici S, Ozdemir C, Kavak A. A Synthetıc Aperture Radar-Based Focusıng Algorıthm For B-Scan Ground Penetratıng Radar Imagery, Mıcrowave And Optıcal Technology Letters / Vol. 49, No. 10, 2007.
  • Yigit E. Construction of synthetic aperture radar system for ground platforms and obtaining real terrestrial radar images, Phd. Thesis, Mersin University, Institute of Science. 2013.
  • Mersereau R, Oppenheim “A. Digital reconstruction of multidimensional signals from their projections”. P IEEE, 62(10): 1319–38, (1974).
  • Demirci S. Yigit E. Eskidemir I.H, Ozdemir C. Ground penetrating radar imaging of water leaks from buried pipes based on back-projection method, NDT&E International 47 (2012) 35–42.
There are 10 citations in total.

Details

Primary Language English
Subjects Engineering
Journal Section Articles
Authors

Enes Yiğit 0000-0002-0960-5335

Umut Özkaya 0000-0002-9244-0024

Şaban Öztürk 0000-0003-2371-8173

Publication Date October 5, 2020
Published in Issue Year 2020 Ejosat Special Issue 2020 (ICCEES)

Cite

APA Yiğit, E., Özkaya, U., & Öztürk, Ş. (2020). Enhancement of Near Field GB-SAR Image Quality Using Beamwidth Filter. Avrupa Bilim Ve Teknoloji Dergisi480-487. https://doi.org/10.31590/ejosat.820286