 |
|
| ALMA-J Site Testing |
 |
 |
 |
| ＞ALMA-J Site Testing Archive |
Last update
2005-01-24
|
Fourier Transform Spectrometer
A Fourier transform spectrometer (FTS) covering a frequency range from 150 GHz to 1.6 THz was fabricated at Nobeyama Radio Observatory. It was used at Pampa la Bola (4800 m a.s.l.) in 1997 September and 1998 June.
Specifications
| Spectrometer | Optics | Martin-Puplett interferometer |
| Beam diameter | 75 mm (F1.6) | |
| Beam width | 10 deg (FWHM) | |
| Throughput | 0.75 cm2 sr | |
| Scan length | (+/-)16.5 mm | |
| Scan speed | 15 mm s-1 | |
| Scan time | 4 s | |
| Resolution | 0.3 cm-1 (10 GHz) | |
| Detector | Bolometer | InSb bolometer |
| Operating temperature | 3.7 K | |
| Frequiency range | 3 - 53 cm-1 (100-1600 GHz) | |
| Noise equivalent power | 1x10-12 W Hz-1/2 | |
| Calibration | Temperature calibrator | Eccosorb AN-74 at LN2 (73 K) and ambient temperature |
| Accuracy | < 5 K at 100-1000 GHz, and up to 10% in transmission at the 1450-1600 GHz window. | |
| System | Total weight | ?? kg |
| Power consumption | ?? W |
Technical Description
Figure 1: Schematic drawing (see Matsuo et al. 1998 for detail).
References
- Matsushita, S., & Matsuo, H. 2003, PASJ, 55, 325;
[astro-ph/0302016]
``FTS measurements of submillimeter-wave atmospheric opacity at Pampa la Bola III: Water Vapor, Liquid Water, and 183 GHz Water Vapor Line Opacities'' - Matsushita, S., Matsuo, H., Wiedner, M. C., & Pardo, J. R. 2002, ALMA Memo, 415
``Phase Correction using Submillimeter Atmospheric Continuum Emission'' - Matsushita, S., & Matsuo, H. 2002, in ASP Conf. Ser. Vol. 266,
Astronomical Site Evaluation in the Visible and Radio Range,
IAU Technical Workshop, ed. J. Vernin, Z. Benkhaldoun, & C. Munoz-Tunon
(San Francisco: ASP), 180
``Relation between 183 GHz Water Vapor Line and Water Continuum Absorption Measured with FTS'' - Matsushita, S., & Matsuo, H. 2001, in Asia-Pacific Radio Science Conference (AP-RASC '01) of URSI, 379
``FTS Observations of Atmospheric Transmission at Pampa la Bola'' - Matsushita, S., & Matsuo, H. 2001, in National Radio Science Meeting of USNC/URSI, 224
``Relation between 183 GHz Water Vapor Line and mm/submm Opacity Measured with FTS'' - Matsushita, S., Matsuo, H., Sakamoto, A., & Pardo, J. R. 2000, Proc. SPIE, 4015, 378
``FTS measurements of submillimeter opacity and other site testing at Pampa la Bola'' - Matsushita, S., Matsuo, H., Pardo, J. R., & Radford, S. J. E. 1999, PASJ, 51, 603; NROR 491
``FTS measurements of submillimeter-wave atmospheric opacity at Pampa la Bola II: Supra-terahertz windows and model fitting'' - Matsuo, H., Matsushita, S. 1999, in National Radio Science Meeting of USNC/URSI, 204
``FTS measurements of submillimeter-wave atmospheric opacity at Pampa la Bola'' - Matsuo, H., Sakamoto, A., & Matsushita, S. 1998, Proc. SPIE, 3357, 626
``FTS measurements of submillimeter-wave opacity at Pampa la Bola'' - Matsuo, H., Sakamoto, A., & Matsushita, S. 1998, PASJ, 50, 359; NROR 453
``FTS measurements of submillimeter-wave atmospheric opacity at Pampa la Bola''
Data
- FTS Data Archive (Calibrated opacity spectra)
- Summary: Opacity Correlations between 220 GHz and submillimeter-wave
Figure 2: Best atmospheric transmission spectrum taken by the FTS. This figure was taken between 10:19 and 10:33, 1998 June 17 in Chilean local time (UT - 4 hours). The rest frequencies for some atomic and molecular lines of astrophysical interest are also overplotted (see Matsushita et al. 1999, 2000 for detail).
If you have any comments or questions, e-mail to Satoki Matsushita or Hiroshi Matsuo