The High Resolution Chirp Transform Spectrometer for the Sofia-Great Instrument
- 175 Downloads
In this paper, we present the design of a high resolution Chirp Transform Spectrometer (CTS) which is part of the GREAT (German REceiver for Astronomy at Terahertz frequencies) instrument onboard SOFIA, the Stratospheric Observatory For Infrared Astronomy. The new spectrometer will provide unique spectral resolving power and linearity response, since the analog Fourier transform performed by the CTS spectrometer was improved through a new design, that we call “Adaptive Digital Chirp Processor (ADCP)”. The principle behind the ADCP consists on digitally generating the dispersive signal which adapts to the compressor dispersive properties, achieving maximum spectral resolution and higher dynamic range. Excellent test results have been obtained such as a white noise dynamic range of 30 dB, and a spectral resolution (FWHM) of 41.68 kHz which would mean if analyzing signals with the high frequency band receiver on the GREAT instrument (4.7 THz) a spectral resolving power (λ/Δ λ) higher than 108.
KeywordsRadio Astronomy High Resolution Spectroscopy Chirp Transform Spectrometer Radiometers Heterodyne Instrumentation
Unable to display preview. Download preview PDF.
- Beaudin, G., Gulkis, S., Frerking, M., Hartogh, P., Allen, M., Bockelee-Morvan, D., Crovisier, J., Despois, D., Encrenaz, P., Encrenaz, T., Germain, B., Hofstadter, M., Ip, W., Janssen, J., Lellouch, E., Mann, I., Muhleman, D., Rauer, H., Schloerb, F.P. and Spilker, T.: 1998, in: Proceedings of the 2nd ESA Workshop on Millimetre Wave Technology and Applications: Antennas, Circuits and Systems (edited by J. Mallat, A. Räisänen, and J. Tuovinen), pp. 43–48, ESA WPP-149, ESA Publ. Div., ESPOO, Finland.Google Scholar
- Hartogh, P.: 1989, Messung der 142,GHz Emissionslinie des atmosphärischen Ozons, PhD thesis, University of Goettingen.Google Scholar
- Hartogh, P. and Jarchow, C.: 1994, in: Proc. IGARSS'94 on Surface and Atmospheric Remote Sensing: Technologies, Data Analysis and Interpretation, Pasadena, Vol. III (edited by T. I. Stein), pp. 3–5, Publ. Services IEEE, Piscataway, N.J.Google Scholar
- Hartogh, P.: 2000, Stratospheric Processes and their Role in Climate (A project of the WMO/ICSU/IOC World Climate Research Programme): SPARC Assessment of Upper Tropospheric and Stratospheric Water Vapour, (edited by D. Kley, J. M. R. III, and C. Phillips), vol. WCRP-113, pp. 45–46, SPARC Office, BP 3, 91371 Verrieres le Buisson Cedex, France.Google Scholar
- Hartogh, P., Jarchow, C., Sonnemann, G.R. and Grygalashvyly, M.: 2004, J. Geophys. Res. 109.Google Scholar
- Nett, H., Crewell, S., Hartogh, P. and Künzi, K.: 1993, in: Proceedings of the International Symposium on Environmental Sensing, vol. 1715 of SPIE, Optical Methods in Atmospheric Chemistry, pp. 468–475, Berlin, 22–26 June 1992.Google Scholar
- Villanueva, G.: 2004, Albert-Ludwigs-Universitat zu Freiburg, PhD thesis.Google Scholar
- Zmuidzinas, J. and Edgar, M.: 1999, Caltech Submillimeter Interstellar Medium Investigations Receiver, SOFIAPADR — Preliminary Airworthiness Design Review document.Google Scholar