No Access

Frequency Reference Stability and Coherence Loss in Radio Astronomy Interferometers Application to the SKA

Bassem Alachkar

http://orcid.org/0000-0003-2560-097X

Jodrell Bank Centre for Astrophysics, School of Physics & Astronomy, University of Manchester, Manchester, UK

E-mail Address: bassem.alachkar@manchester.ac.uk

Search for more papers by this author

Althea Wilkinson

Jodrell Bank Centre for Astrophysics, School of Physics & Astronomy, University of Manchester, Manchester, UK

Search for more papers by this author

, and

Keith Grainge

Jodrell Bank Centre for Astrophysics, School of Physics & Astronomy, University of Manchester, Manchester, UK

Search for more papers by this author

https://doi.org/10.1142/S2251171718500010Cited by:4 (Source: Crossref)

Abstract

The requirements on the stability of the frequency reference in the square Kilometer array (SKA), as a radio astronomy interferometer, are given in terms of the maximum accepted degree of coherence loss caused by the instability of the frequency reference. In this paper, we analyze the relationship between the characterization of the instability of the frequency reference in the radio astronomy array and the coherence loss. The calculation of the coherence loss from the instability characterization given by the Allan deviation is reviewed. A model of a typical frequency distribution system is presented. The verification of the coherence and frequency reference stability requirements is discussed. Some practical aspects and limitations relevant to the SKA are analyzed.

Keywords:

References

Allan, D. W. [1966] “Statistics of atomic frequency standards,” in Proc. IEEE 54, 221–230. Google Scholar
Barnes, J. A. et al. [1971] “Characterization of frequency stability,” IEEE Trans. Instrum. Meas. IM-20, 105–120. Crossref, ADS, Google Scholar
Dewdney, P. E., Hall, P. J., Schilizzi, R. T. & Lazio, T. J. L. W. [2009] “The square kilometre array,” in Proc. IEEE 97, 1482–1496. Google Scholar
Filler, R. L. [1988] “The acceleration sensitivity of quartz crystal oscillators: A review,” IEEE Trans. Ultrason., Ferroelect. Freq. Contr. 35, 297–305. Crossref, Google Scholar
Grainge, K. et al. [2017] “Square kilometre array: The radio telescope of the XXI century,” Astron. Rep. 61 (4), 288–296. Crossref, ADS, Google Scholar
Kawaguchi, N. [1983] “Coherence loss and delay observation error in very-long-baseline interferometry,” J. Radio Res. Lab. 30 (129), 59–87. Google Scholar
Lindsey, W. C. & Chie, C. M. [1976] “Theory of oscillator instability based upon structure function,” in Proc. IEEE 64, 1652–1666. Google Scholar
Rogers, A. E. E. & Moran, J. M. [1981] “Coherence limits for very-long-baseline interferometry,” IEEE Trans. Instrum. Meas. IM-30 (4), 283–286. Crossref, ADS, Google Scholar
Rutman, J. [1978] “Characterization of phase and frequency instabilities in precision frequency sources: Fifteen years of progress,” in Proc. IEEE 66, 1048–1075. Google Scholar
Schediwy, S., Gozzard, D., Stobie, S., Malan, J. & Grainge, K. [2017] “Stabilized microwave-frequency transfer using optical phase sensing and actuation,” Opt. Lett. 42 (9), 1648–1651. Crossref, ADS, Google Scholar
Thompson, A. R., Moran, J. M. & Swenson Jr. G. W. [2017] Interferometry and Synthesis in Radio Astronomy, 3rd edition (Springer Open). Crossref, Google Scholar
Wang, B., Zhu, X., Gao, C., Bai, Y., Dong, J. W. & Wang, L. J. [2015] “Square kilometer array telescope — Precision reference frequency synchronisation via 1f-2f dissemination,” Sci. Rep. 5, 13851. Crossref, ADS, Google Scholar
Williams, P. A., Swann, W. C. & Newbury, N. R. [2008] “High stability transfer of an optical frequency over long fiber optic links,” J. Opt. Soc. Am. B 25, 1284. Crossref, ADS, Google Scholar