Instruments:aop

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Abastumani Atsrophysical Observatory, Georgia

Contents


-Revised 07 Aug 2009 by Barbara Emery

Contact Persons

Web Sites

Acknowledgments

  • The Georgian National Astrophysical Observatory at Ilia Chavchavadze State University, formerly the Abastumani Astrophysical Observatory, is supported by the Ministry of Education and Science of Georgia.

Instrument/Model Description

The Abastumani Astrophysical Observatory (41.75405 N, 42.818442 E; 36.7 magN; 1595m msl alt) is located in Georgia. The official name of this observatory is now 'The Georgian National Astrophysical Observatory at Ilia Chavchavadze State Univerity", where the University is located in Tbilisi, Georgia. The apex magnetic coordinates at 100 km height at the start of 1974 were (36.7, 114.0), with a magentic declination of 4.3 degrees, an inclination of 59.2 degrees, and 0 UT at 0231 MLT.

Several instruments collected nighttime optical observations, with the earliest observations made in 1942. The spectrograph data is on film and the older photometrical data are on paper charts, many of which have been digitized. The length of the data sets makes them attractive for long-term studies. The local time (LT) is UT plus 3 hours, or UT = LT - 3. In the original files and in the CEDAR DB files, the LT time is the middle time.

The exposure time for [O] data from 1957-1973 and 1974-1993 was ~2 min and ~1.5 min, respectively, so the begin and end times were assumed to be 1 min earlier and later than the middle time.

Nighttime brightness observations come from several instruments over time. The total wavelength width (dlambda) at the Full Width at Half Maximum (FWHM) is located at half the peak intensity. The listed bandpass for the Abastumani instruments is equal to the FWHM or dlambda, while other definitions call bandpass dlambda/2. We will refer to FWHM for clarity.

Observation targets are:

  1. Absorption and some intensity lines (nm range?) on film at twilight: 1942-present (spectrograph SP48, ..)
  2. Total ozone [O3] content in Dobson units (~250-300? nm): 1957-1964 (?), 1965-1993 (photometer), 1994 and 1996-present (?). Daily total ozone content values from 1957-2004 are available at http://www.observatory.iliauni.edu.ge
  3. Atomic oxygen [O] green (557.7nm) and red (630.0 nm) lines: 1957-1973 (3-filter spectrometer with [Na]), 1974-1993 (3-filter photometer with [OH]), 2004-2008 (2-channel photometer). Zenith observations from 1957-1993 are at http://www.genao.org/UpAtm.
  4. Sodium [Na] doublet (~589.0nm and ~589.6nm or ~589.3nm): 1957-1973 (spectrometer with [O]), 1974 (3-filter photometer with [O]).
  5. Geocorona [H] alpha (~656.3 nm) pointed at 42 degrees elevation north (N) to the North Star with background continuum [NO2 mostly] and various [OH], especially OH(6-1) R1 ~647.3 nm: 1958-1969 (3-filter spectrograph SP48), 1968-1987 (interferometer), 1987-1997 and 2006-present (3-filter photometer: [H] 0.55 nm FWHM, OH(6-1) 1.35 nm FWHM, background [NO2] continuum ~675.4 nm with 1.25 nm FWHM). January 2008 plots of [H] alpha geocorona are at http://www.genao.org/UpAtm and http://www.observatory.iliauni.edu.ge.
  6. Various hydroxyl [OH] bands:
    1. OH(9-3) P1 ~635.? nm nm?
    2. OH(6-1) R1 ~647.3 nm (with [H] alpha)
    3. OH(6-1) P1 ~660.? nm, nm?
    4. OH(8-3) R1 ~724.6 nm (with red/green [O])

1957-1974 (1-3 filter photometer), 1968-1987 (interferometer with [H]), 1974-1993 (3-filter photometer with [O]), 1987-1992 and 2006-present (3-filter photometer with [H]) Jan 2008 plots of OH(6-1) R1 are at http://www.genao.org/UpAtm and http://www.observatory.iliauni.edu.ge.

This header is specifically for the atomic oxygen [O] red line emissions at ~630.0 nm at ~240+/-25km using the spectrometer (1957-1973) in all directions and the 3-filter photometer (1974-1993). The zenith observations are at http://www.genao.org/UpAtm. Further details of the [O] instruments are:

  1. kindat=6301: 1957-1973 Diffraction grating spectrometer for [O] green and red and [Na] doublet, (100?nm range from 550? nm to 650?nm, ~2 min observations, ~30 min cycle time, on film, digitized from paper charts so the LT is the middle time, pointed to zenith mostly (only data used), and pointed to geographic north (N) between 20 and 70 degrees elevation, and south (S) between 23 and 70 degrees elevation, where most of the off-zenith observations were taken at 23 degrees elevation N and S. Zenith observations for the red and green lines from 1957-1993 are at: http://www.genao.org/UpAtm
  2. kindat=6302: 1974-1993, Photometer with 3 filters pointed to zenith with 5 deg Field-of-View (FOV). ~1.5 min exposture for each filter, ~7 min cycle for 3 filters, on paper but digitized so the LT is the middle time. The [Na] doublet was only observed Jan-Jun 1974 instead of [OH].
    1. [O] green line (~557.7 nm, 49% transmission, FWHM 4 nm, min-max filter range of 551.7-563.7 nm on ?? date)
    2. [O] red line (~630.0 nm, 57% transmission, FWHM 3.8 nm, min-max filter range of 622.8-637.9 nm in 1973)
    3. OH(8-3) R1 branch (~724.6 nm, 47.8% transmission, FWHM 4.0 nm, min- max filter range at 1% transmission 718.0-732.5 nm on 4 April 1977). Zenith observations for the red and green lines from 1957-1993 are at: http://www.genao.org/UpAtm
    4. kindat=6303: 2004-2008, Two-channel Photometer pointed 45 deg elevation with 5 degree FOV, ~15 sec observations simultaneously for each filter of the red and green [O] lines at ~630.0 nm and ~557.7 nm to N, E, S, W and ~15 sec observations of background for a cycle time of ~2 min. The red line filter has 53% transmission, FWHM 2.5 nm. Plots of the red and green line intensities from 2004-2006 are at: http://www.genao.org/UpAtm.

Many of the early observations from 1957-1993 were made by Prof. L. Fishkova and Dr. N. Marcvaladze. After the mid 1970's, they used the Einstein Transition Probabilities from Mies (1974).



Older text on red/green [O] and other filters kept for now

    1. 1974-1993 resolution 3 min for each filter used (3 filters with the OH band filter (8-3) R1(??) branch centered on 726.4 nm(???))
      OH(8-3) R1 from Chamberlain, p 370, Physics of the Aurora and Airglow
      K''=1 724.48
      K''=2 723.98
      K''=3 723.80
      K''=4 723.92
      K''=5 724.42
      K''=6 725.33
      K''=7 726.51 1993-2000 gap 2000-present same 3 min resolution
  1. Photometer OH bands (filters for 6-1, 9-3, etc??) from 1957-1974, intermittent thereafter. Sometimes used 1 filter, 2 filters, or 3 filters (??).
    1. 1958-1970 (missing 1965-1967) OH(9-3) and OH(6-1) P1 branches (J=3/2) centered at 635 nm and 660 nm (? kindats 6350 and 6600): Have arbitrary brightness for entire night (Fishkova et al REF???) Second nm numbers are from Chamberlain, p 370, Physics of the Aurora and Airglow
      OH(9-3) OH(6-1)
      P1 628.7 628.76 653.3 653.31
      P2 630.6 630.68 655.4 655.37
      P3 632.9 632.92 657.4 657.73
      P4 635.6 635.51 660.3 660.41
      P5 638.6 638.44 663.3 663.42
      P6 642.0 641.69 666.7 666.75
    2. 1987-1993 OH(6-1) R1 branch centered at 647.3 nm (kindat=6470) between 64?.? nm and 64?.? nm (or wavenumber) every 3 min pointed at azimuth 180 (geographic south) and 42 deg elevation angle above the horizon with a field-of-view of ???.
      OH(6-1) R1 from Chamberlain, p 370, Physics of the Aurora and Airglow
      K''=1 647.10
      K''=2 646.60
      K''=3 646.36
      K''=4 646.38
      K''=5 646.69
      K''=6 647.28
      K''=7 648.17

References for the Technique, Station, and Data

Fishkova, L. M., The night airglow of the Earth midlatitude upper atmosphere, Metsniereba press, Tbilisi, 1983. (in Russian)
Gudadze, N. B., G. G. Didebulidze, L. N. Lomidze, G. Sh. Javakhishvili, M. A. Marsagishvili, and M. Todua, Different long-term trends of the oxygen red 630.0nm line nightglow intensity as the result of lowering the ionosphere F2 layer, Ann. Geophys., 26, 2069-2080, 2008.
Martsvaladze, N. M. and L. M. Fishkova, Radiation of the upper atmosphere and geocoronal hydrogen in 1958-1988 on observation of the HI 656.3nm emission in Abastumani, Geomagn. Aeron., 31(6), 1017-1020, 1991 (in Russian).
Mayer, A. K. and L. M. Fishkova, An electrophotometer with the narrow-band light filter for observations of hydrogen emission in the Earth's upper atmosphere, Bull. Abastumani Astrophys., Observ., No. 66, 1988, 259-266. (in Russian)
Mies, F. H., Calculated vibrational transition probabilities of OH(X^2PI), J. Molec. Spectroscopy, 53, 150-188, 1974.

Older Summary Plots from 2003 with the 630nm [O] plots from 2009 at the very end

Summary Plots for Abastumani OH(6-1) P1 Branch (P2 peak) Relative Brightness

Summary Plots for Abastumani OH(9-3) P1 Branch (P2 peak) Relative Brightness

Summary Plots for Abastumani OH(6-1) R1 Photometer

Summary Plots for Abastumani OH(8-3) R1 Photometer (same times as red and green [O] lines)

Summary Plots for Abastumani [O] green line Photometer (same times as red line and OH(8-3))

Summary Plots for Abastumani [O] red line Photometer (same times as green line and OH(8-3)) from 2003


Summary Plots for Abastumani 630 nm [O] red line photometer intensities (revised in 2009)