© The Institution of Engineering and Technology
A simple method for spectral estimation of terahertz signals using an autoregressive model is developed. The technique shows a better spectral variance and resolution over the use of the Fast Fourier Transform, which is commonly utilised in this kind of signal. The results are validated comparing the water vapour absorption lines and the standard deviation of a set of 24 measurements between methods. As a consequence of improving the signal variance, a better signal-to-noise ratio is achieved without enhancing the experiment. Such result also produces an increase in the signal bandwidth and less error when optical parameters are estimated.
References
-
-
1)
-
2. Stoica, P., Moses, R.: ‘Spectral analysis of signals’ (Prentice-Hall, USA, 2005).
-
2)
-
1. Schlindwein, F.S., Evans, D.H.: ‘Autoregressive spectral analysis as an alternative to fast Fourier transform analysis of Doppler ultrasound signals’, in Arnold, E. (ED.): ‘Diagnostic vascular ultrasound’ , vol. 8, pp. 74–84.
-
3)
-
3. Tych, K.M., Wood, C.D., Tych, W.: ‘A simple transfer function based approach for estimating material parameters from Terahertz time-domain data’, IEEE Photonics J., 2014, 6, pp. 1–11 (doi: 10.1109/JPHOT.2013.2292337).
-
4)
-
4. Ljung, L.: ‘System identification’ (Prentice-Hall, USA, 1999).
-
5)
-
5. Van Exter, M., Fattinger, Ch., Grischkowsky, D.: ‘Terahertz time-domain spectroscopy of water vapor’, Opt. Lett., 1989, 14, pp. 1128–1130 (doi: 10.1364/OL.14.001128).
-
6)
-
6. Cheville, R.A., Grischkowsky, D.: ‘Far-infrared foreign and self-broadened rotational linewidths of high-temperature water vapor’, J. Opt. Soc. Am. B, 1999, 16, pp. 317–322 (doi: 10.1364/JOSAB.16.000317).
http://iet.metastore.ingenta.com/content/journals/10.1049/el.2015.2955
Related content
content/journals/10.1049/el.2015.2955
pub_keyword,iet_inspecKeyword,pub_concept
6
6
Correspondence
This article has following corresponding article(s):
in brief