A Study on the Digital Filter Design using Software for Analysis of Observation Data in Radio Astronomy

전파천문 관측데이터 분석을 위해 소프트웨어를 이용한 디지털필터 설계에 관한 연구

  • Received : 2015.09.15
  • Accepted : 2015.11.08
  • Published : 2015.10.30

Abstract

In this paper, we propose a design method for a digital filter using software in order to analyze the radio astronomy observation data. Recently the analysis method for radio astronomy observing system is transferring from hardware to software by developing of state-of-the-art of computer system. The existing hardware system is not able to easily change the specification because it is implemented to meet special requirements and it takes a high cost and time. In case of software, however, it has an advantage to implement with small cost if open software is used, and flexibly changes to satisfy the desired specification. But, in order to analyze the massive data like radio astronomy with software, the good performance system is needed for computer. Therefore, this paper proposes a digital filter design method using software with the same performance as that of digital filter implemented with hardware in observation system which is operated by the KVN(Korean VLBI Network). To design a digital filter, the proposed method is performed with standard C language and the simulation is conducted with GNU(GNU's Not Unix) Octave and investigated to show its effectiveness. In addition, for the high speed operation of the designed digital filter, the SSE(Streaming SIMD Extensions) library is adopted for available parallel operation. By the proposed digital filter, the digital filtering is performed for the wide band observation data in the KVN observation mode, the filtering result of narrow band observation has no ripple inside of stop band, and confirmed the effectiveness of the proposed method.

References

  1. 노덕규, 오세진, 염재환 외 15명, "2008년도 한일공동VLBI상관기 및 수신기 개발 결과보고서," 한국천문연구원, pp. 3-100, 2008.
  2. Takahashi F., Kondo T., and Koyama Y., Very Long Baseline Interferometer, Ohmsha, pp. 35-55. 2000.
  3. Thompson, A. R., Moran, J. M., and Swenson, G. W.Jr., Interferometry and Synthesis in Radio Astronomy, 2nd Ed., (New York:John Wiley & Sons), pp. 289, 2001.
  4. Se-Jin Oh, Duk-Gyoo Roh, Kiyoaki Wajima et. al., "Design and Development of a High-Speed Data Acquisition System for the Korean VLBI Network," Publication of Astronomical Society of Japan, Vol. 63, pp. 1229-1242, 2011 December 25. https://doi.org/10.1093/pasj/63.6.1229
  5. 오세진, 염재환, 노덕규 외 9명, "한일상관기의 잔차지연보정 알고리즘의 개선," 신호처리시스템학회 논문지 제14권, 제2호, pp. 136-146, 2013.
  6. Alan V. Oppenheim and Ronald W. Schafer, Discrete-Time Signal Processing, Prentice Hall, Chapter 9, 1989.
  7. 황운택, "Kaiser 창함수를 이용한 비회귀 디지털 필터 설계," 한국통신학회 전문대학 논문지, Vol. 5, No. 1, pp. 506-514, 1995.
  8. Sophocles J. Orfanidis, Introduction to Signal Processing, Prentice Hall, Chapter 10, 1996.
  9. University of Newcastle Upon Tyne, Digital Signal Processing EEE305 & EEE801 Part A, Chapter 4, 2002.
  10. 오세진, 노덕규, 김광동 외 5명, "관측 데이터의 고속기록을 위한 대용량 저장시스템," 천문학논총, 제19권, pp. 83-92, 2004.