Abstract

A Fabry-Perot spectrometer specifically designed for measuring airglow intensities in twilight has been built using a feedback-controlled etalon from Queensgate Instruments, London. A single etalon passband (FWHM = 0.015 nm at 558 nm) is isolated by a narrowband (0.2-nm) interference filter. The passband of the etalon can be shifted in a random fashion by a digital command to a controlling circuit. Observing time is, therefore, used efficiently because only wavelengths of interest need be observed. Responsivity of the system is 1.3 counts sec−1 R−1 at 558 nm. The optics are contained in an outdoor climate-controlled enclosure connected by cables to a microcomputer at the indoor observing station. The computer controls all functions of the instrument and is capable of running long complex observing routines unattended using parameters specified by the observer. These parameters include meridian angles, filters (up to eight), integration times, and etalon steps. Some examples of twilight measurements are given.

© 1983 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. B. W. Currie, H. W. Edwards, Terr. Mag. 41, 265 (1936).
    [CrossRef]
  2. R. Bernard, Z. Phys. 110, 291 (1938).
    [CrossRef]
  3. J. Cabannes, J. Dufay, J. Gauzit, C. R. Acad. Sci. 206, 870 (1938).
  4. W. A. Gault, H. N. Rundle, Can. J. Phys. 47, 85 (1969).
    [CrossRef]
  5. P. B. Hays, G. Carignan, B. C. Kennedy, G. G. Shepherd, J. C. G. Walker, Radio Sci. 8, 369 (1973).
    [CrossRef]
  6. P. Jacquinot, J. Opt. Soc. Am. 44, 761 (1954).
    [CrossRef]
  7. G. G. Shepherd, Ann. Geophys. 25, 841 (1969).
  8. G. Hernandez, O. A. Mills, J. L. Smith, Appl. Opt. 20, 3687 (1981).
    [CrossRef] [PubMed]
  9. G. Hernandez, Appl. Opt. 21, 507 (1982).
    [CrossRef] [PubMed]

1982

1981

1973

P. B. Hays, G. Carignan, B. C. Kennedy, G. G. Shepherd, J. C. G. Walker, Radio Sci. 8, 369 (1973).
[CrossRef]

1969

G. G. Shepherd, Ann. Geophys. 25, 841 (1969).

W. A. Gault, H. N. Rundle, Can. J. Phys. 47, 85 (1969).
[CrossRef]

1954

1938

R. Bernard, Z. Phys. 110, 291 (1938).
[CrossRef]

J. Cabannes, J. Dufay, J. Gauzit, C. R. Acad. Sci. 206, 870 (1938).

1936

B. W. Currie, H. W. Edwards, Terr. Mag. 41, 265 (1936).
[CrossRef]

Bernard, R.

R. Bernard, Z. Phys. 110, 291 (1938).
[CrossRef]

Cabannes, J.

J. Cabannes, J. Dufay, J. Gauzit, C. R. Acad. Sci. 206, 870 (1938).

Carignan, G.

P. B. Hays, G. Carignan, B. C. Kennedy, G. G. Shepherd, J. C. G. Walker, Radio Sci. 8, 369 (1973).
[CrossRef]

Currie, B. W.

B. W. Currie, H. W. Edwards, Terr. Mag. 41, 265 (1936).
[CrossRef]

Dufay, J.

J. Cabannes, J. Dufay, J. Gauzit, C. R. Acad. Sci. 206, 870 (1938).

Edwards, H. W.

B. W. Currie, H. W. Edwards, Terr. Mag. 41, 265 (1936).
[CrossRef]

Gault, W. A.

W. A. Gault, H. N. Rundle, Can. J. Phys. 47, 85 (1969).
[CrossRef]

Gauzit, J.

J. Cabannes, J. Dufay, J. Gauzit, C. R. Acad. Sci. 206, 870 (1938).

Hays, P. B.

P. B. Hays, G. Carignan, B. C. Kennedy, G. G. Shepherd, J. C. G. Walker, Radio Sci. 8, 369 (1973).
[CrossRef]

Hernandez, G.

Jacquinot, P.

Kennedy, B. C.

P. B. Hays, G. Carignan, B. C. Kennedy, G. G. Shepherd, J. C. G. Walker, Radio Sci. 8, 369 (1973).
[CrossRef]

Mills, O. A.

Rundle, H. N.

W. A. Gault, H. N. Rundle, Can. J. Phys. 47, 85 (1969).
[CrossRef]

Shepherd, G. G.

P. B. Hays, G. Carignan, B. C. Kennedy, G. G. Shepherd, J. C. G. Walker, Radio Sci. 8, 369 (1973).
[CrossRef]

G. G. Shepherd, Ann. Geophys. 25, 841 (1969).

Smith, J. L.

Walker, J. C. G.

P. B. Hays, G. Carignan, B. C. Kennedy, G. G. Shepherd, J. C. G. Walker, Radio Sci. 8, 369 (1973).
[CrossRef]

Ann. Geophys.

G. G. Shepherd, Ann. Geophys. 25, 841 (1969).

Appl. Opt.

C. R. Acad. Sci.

J. Cabannes, J. Dufay, J. Gauzit, C. R. Acad. Sci. 206, 870 (1938).

Can. J. Phys.

W. A. Gault, H. N. Rundle, Can. J. Phys. 47, 85 (1969).
[CrossRef]

J. Opt. Soc. Am.

Radio Sci.

P. B. Hays, G. Carignan, B. C. Kennedy, G. G. Shepherd, J. C. G. Walker, Radio Sci. 8, 369 (1973).
[CrossRef]

Terr. Mag.

B. W. Currie, H. W. Edwards, Terr. Mag. 41, 265 (1936).
[CrossRef]

Z. Phys.

R. Bernard, Z. Phys. 110, 291 (1938).
[CrossRef]

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (6)

Fig. 1
Fig. 1

Optical system. Light from the sky reflects from the meridian scanning mirror M1, enters the insulated box through W, and passes through the system. The drawing is approximately to scale.

Fig. 2
Fig. 2

Relative transmittance spectra for PRESTO. The narrow band, the etalon transmission curve, is the empirical result of scanning a narrow spectral line. The filter transmission function was measured on a laboratory spectrometer with a 0.02-nm spectral slit width. The outer curve is the spectral response of PRESTO to a white light (incandescent) source.

Fig. 3
Fig. 3

Sky spectrum at 558 nm during evening twilight of 9 Dec. 1982 over Toronto. Dashed curves indicate white light spectrum used for background subtraction. Note that each spectrum uses a different ordinate scale.

Fig. 4
Fig. 4

Twilight OI 558-nm decay on 9 Dec. 1982 over Toronto deduced from sky spectra represented by those in Fig. 3. Ordinates employ a responsivity of 6.5 R/count (the frequency divider was in use) and a van Rhijn factor of 2. Valid readings were obtained for solar depression angles of 3° or more.

Fig. 5
Fig. 5

Example of a spectral scan from the CENTAUR data taken at 1943 UT (2.6° solar depression) on day 339,1981 looking at 60° altitude in the south. The emission rate for OI 6300 nm in this case is 6 kR. A frequency divider was used to reduce the count rate.

Fig. 6
Fig. 6

Two meridian scans taken at Cape Parry during the CENTAUR campaign. They were measured during the evening twilight of day 339 1981 at solar depression angles of 3.1 and 6.0°. The background subtraction was done without operator intervention. The larger scatter at 3.1° is probably due to the much brighter background continuum at this time.

Metrics