Abstract

A large throughput transmission spectrometer, with a grating on a prism as the diffraction element, has been developed to study altitude distributions of auroral emissions. The imaging spectrometer disperses spectrally in one dimension while spatial information is preserved in the orthogonal direction. The image is projected onto a CCD array detector. Image processing methods have been developed to calibrate for wavelength, uniform field, spectral sensitivity, curvature of field, and spatial mapping. Single images are processed to represent a measured signal brightness in a unit of Rayleighs/pixel, from which area integrations can be made for desired spatial–spectral resolution. System performance is ∼1.5-nm resolution over a 450-nm bandwidth (420–870 nm). Two spectrometer systems of this design were operated simultaneously, one with additional optical instruments and an incoherent scatter radar at Sondrestrom, Greenland, and the other at Godhavn, Greenland, which lies 290 km to the northwest and nearly in the magnetic meridian of Sondrestrom. The developed system, calibration method, and examples of performance results are presented.

© 1998 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. M. H. Rees, “Auroral ionization and excitation by incident energetic electrons,” Planet. Space Sci. 11, 1209–1218 (1963).
    [CrossRef]
  2. M. H. Rees, D. Luckey, “Auroral electron energy derived from ratio of spectroscopic emissions. 1. Model computations,” J. Geophys. Res. 79, 5181–5186 (1974).
    [CrossRef]
  3. D. J. Strickland, R. R. Meier, J. H. Hecht, A. B. Christensen, “Deducing composition and incident electron spectra from ground-based optical measurements: theory and model results,” J. Geophys. Res. 94, 13,527–13,539 (1989).
    [CrossRef]
  4. C. Störmer, The Polar Aurora, Clarendon, Oxford, 1955.
  5. J. G. Romick, A. E. Belon, “The spatial variation of auroral luminosity. II. Determination of volume emission rate profiles,” Planet. Space Sci. 15, 1695–1716 (1967).
    [CrossRef]
  6. A. V. Jones, “Optical emissions from aurora,” in Aurora, Vol. 9 of Geophysics and Astrophysics Monograph (Reidel, Norwell, Mass., 1974), pp. 80–128.
    [CrossRef]
  7. A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. II. The spectrum of medium intensity aurora between 4500 and 8900 Å,” Can. J. Phys. 52, 2343–2356 (1974).
  8. A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. III. The spectrum of medium intensity aurora between 3100 and 4700 Å,” Can. J. Phys. 53, 1806–1813 (1975).
    [CrossRef]
  9. G. R. Swenson, S. B. Mende, K. S. Clifton, “Ram vehicle glow spectrum: implication of NO2 recombination continuum,” Geophys. Res. Lett. 12, 97–100 (1985).
    [CrossRef]
  10. S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
    [CrossRef]
  11. R. Rairden, G. R. Swenson, “New imaging spectrometer for auroral research,” in Optical Spectroscopic Techniques and Instrumentation for Atmospheric and Space Research, J. Wang, P. B. Harp, eds., Proc. SPIE2266, 221–230 (1994).
    [CrossRef]
  12. J. D. Kelly, C. J. Heinselman, J. F. Vickrey, R. R. Vondrak, “The Sondrestrom radar and accompanying ground-based instrumentation,” Space Sci. Rev. 71, 797–813 (1995).
    [CrossRef]
  13. S. B. Mende, R. H. Eather, “Monochromatic all-sky observations and auroral precipitation patterns,” J. Geophys. Res. 81, 3771–3780 (1976).
    [CrossRef]
  14. J. V. Evans, “Theory and practice of ionsphere study by Thomson scatter radar,” IEEE Proc. 57, 496–530 (1969).
    [CrossRef]
  15. J. H. Hecht, A. B. Christensen, D. J. Strickland, R. R. Meier, “Deducing composition and incident electron spectra from ground-based auroral optical measurements: variations in oxygen density,” J. Geophys. Res. 94, 13,553–13,563 (1989).
    [CrossRef]
  16. J. L. Semeter, “Ground based tomography of atmoshperic optical emissions,” Ph.D. dissertation (Boston University, Boston, Mass., 1997).

1995 (1)

J. D. Kelly, C. J. Heinselman, J. F. Vickrey, R. R. Vondrak, “The Sondrestrom radar and accompanying ground-based instrumentation,” Space Sci. Rev. 71, 797–813 (1995).
[CrossRef]

1989 (2)

J. H. Hecht, A. B. Christensen, D. J. Strickland, R. R. Meier, “Deducing composition and incident electron spectra from ground-based auroral optical measurements: variations in oxygen density,” J. Geophys. Res. 94, 13,553–13,563 (1989).
[CrossRef]

D. J. Strickland, R. R. Meier, J. H. Hecht, A. B. Christensen, “Deducing composition and incident electron spectra from ground-based optical measurements: theory and model results,” J. Geophys. Res. 94, 13,527–13,539 (1989).
[CrossRef]

1986 (1)

S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
[CrossRef]

1985 (1)

G. R. Swenson, S. B. Mende, K. S. Clifton, “Ram vehicle glow spectrum: implication of NO2 recombination continuum,” Geophys. Res. Lett. 12, 97–100 (1985).
[CrossRef]

1976 (1)

S. B. Mende, R. H. Eather, “Monochromatic all-sky observations and auroral precipitation patterns,” J. Geophys. Res. 81, 3771–3780 (1976).
[CrossRef]

1975 (1)

A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. III. The spectrum of medium intensity aurora between 3100 and 4700 Å,” Can. J. Phys. 53, 1806–1813 (1975).
[CrossRef]

1974 (2)

A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. II. The spectrum of medium intensity aurora between 4500 and 8900 Å,” Can. J. Phys. 52, 2343–2356 (1974).

M. H. Rees, D. Luckey, “Auroral electron energy derived from ratio of spectroscopic emissions. 1. Model computations,” J. Geophys. Res. 79, 5181–5186 (1974).
[CrossRef]

1969 (1)

J. V. Evans, “Theory and practice of ionsphere study by Thomson scatter radar,” IEEE Proc. 57, 496–530 (1969).
[CrossRef]

1967 (1)

J. G. Romick, A. E. Belon, “The spatial variation of auroral luminosity. II. Determination of volume emission rate profiles,” Planet. Space Sci. 15, 1695–1716 (1967).
[CrossRef]

1963 (1)

M. H. Rees, “Auroral ionization and excitation by incident energetic electrons,” Planet. Space Sci. 11, 1209–1218 (1963).
[CrossRef]

Belon, A. E.

J. G. Romick, A. E. Belon, “The spatial variation of auroral luminosity. II. Determination of volume emission rate profiles,” Planet. Space Sci. 15, 1695–1716 (1967).
[CrossRef]

Christensen, A. B.

J. H. Hecht, A. B. Christensen, D. J. Strickland, R. R. Meier, “Deducing composition and incident electron spectra from ground-based auroral optical measurements: variations in oxygen density,” J. Geophys. Res. 94, 13,553–13,563 (1989).
[CrossRef]

D. J. Strickland, R. R. Meier, J. H. Hecht, A. B. Christensen, “Deducing composition and incident electron spectra from ground-based optical measurements: theory and model results,” J. Geophys. Res. 94, 13,527–13,539 (1989).
[CrossRef]

Clifton, K. S.

S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
[CrossRef]

G. R. Swenson, S. B. Mende, K. S. Clifton, “Ram vehicle glow spectrum: implication of NO2 recombination continuum,” Geophys. Res. Lett. 12, 97–100 (1985).
[CrossRef]

Eather, R. H.

S. B. Mende, R. H. Eather, “Monochromatic all-sky observations and auroral precipitation patterns,” J. Geophys. Res. 81, 3771–3780 (1976).
[CrossRef]

Evans, J. V.

J. V. Evans, “Theory and practice of ionsphere study by Thomson scatter radar,” IEEE Proc. 57, 496–530 (1969).
[CrossRef]

Garriott, O. K.

S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
[CrossRef]

Gattinger, R. L.

A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. III. The spectrum of medium intensity aurora between 3100 and 4700 Å,” Can. J. Phys. 53, 1806–1813 (1975).
[CrossRef]

A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. II. The spectrum of medium intensity aurora between 4500 and 8900 Å,” Can. J. Phys. 52, 2343–2356 (1974).

Gause, R.

S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
[CrossRef]

Hecht, J. H.

D. J. Strickland, R. R. Meier, J. H. Hecht, A. B. Christensen, “Deducing composition and incident electron spectra from ground-based optical measurements: theory and model results,” J. Geophys. Res. 94, 13,527–13,539 (1989).
[CrossRef]

J. H. Hecht, A. B. Christensen, D. J. Strickland, R. R. Meier, “Deducing composition and incident electron spectra from ground-based auroral optical measurements: variations in oxygen density,” J. Geophys. Res. 94, 13,553–13,563 (1989).
[CrossRef]

Heinselman, C. J.

J. D. Kelly, C. J. Heinselman, J. F. Vickrey, R. R. Vondrak, “The Sondrestrom radar and accompanying ground-based instrumentation,” Space Sci. Rev. 71, 797–813 (1995).
[CrossRef]

Jones, A. V.

A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. III. The spectrum of medium intensity aurora between 3100 and 4700 Å,” Can. J. Phys. 53, 1806–1813 (1975).
[CrossRef]

A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. II. The spectrum of medium intensity aurora between 4500 and 8900 Å,” Can. J. Phys. 52, 2343–2356 (1974).

A. V. Jones, “Optical emissions from aurora,” in Aurora, Vol. 9 of Geophysics and Astrophysics Monograph (Reidel, Norwell, Mass., 1974), pp. 80–128.
[CrossRef]

Kelly, J. D.

J. D. Kelly, C. J. Heinselman, J. F. Vickrey, R. R. Vondrak, “The Sondrestrom radar and accompanying ground-based instrumentation,” Space Sci. Rev. 71, 797–813 (1995).
[CrossRef]

Leger, L.

S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
[CrossRef]

Luckey, D.

M. H. Rees, D. Luckey, “Auroral electron energy derived from ratio of spectroscopic emissions. 1. Model computations,” J. Geophys. Res. 79, 5181–5186 (1974).
[CrossRef]

Meier, R. R.

J. H. Hecht, A. B. Christensen, D. J. Strickland, R. R. Meier, “Deducing composition and incident electron spectra from ground-based auroral optical measurements: variations in oxygen density,” J. Geophys. Res. 94, 13,553–13,563 (1989).
[CrossRef]

D. J. Strickland, R. R. Meier, J. H. Hecht, A. B. Christensen, “Deducing composition and incident electron spectra from ground-based optical measurements: theory and model results,” J. Geophys. Res. 94, 13,527–13,539 (1989).
[CrossRef]

Mende, S. B.

S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
[CrossRef]

G. R. Swenson, S. B. Mende, K. S. Clifton, “Ram vehicle glow spectrum: implication of NO2 recombination continuum,” Geophys. Res. Lett. 12, 97–100 (1985).
[CrossRef]

S. B. Mende, R. H. Eather, “Monochromatic all-sky observations and auroral precipitation patterns,” J. Geophys. Res. 81, 3771–3780 (1976).
[CrossRef]

Rairden, R.

R. Rairden, G. R. Swenson, “New imaging spectrometer for auroral research,” in Optical Spectroscopic Techniques and Instrumentation for Atmospheric and Space Research, J. Wang, P. B. Harp, eds., Proc. SPIE2266, 221–230 (1994).
[CrossRef]

Rees, M. H.

M. H. Rees, D. Luckey, “Auroral electron energy derived from ratio of spectroscopic emissions. 1. Model computations,” J. Geophys. Res. 79, 5181–5186 (1974).
[CrossRef]

M. H. Rees, “Auroral ionization and excitation by incident energetic electrons,” Planet. Space Sci. 11, 1209–1218 (1963).
[CrossRef]

Romick, J. G.

J. G. Romick, A. E. Belon, “The spatial variation of auroral luminosity. II. Determination of volume emission rate profiles,” Planet. Space Sci. 15, 1695–1716 (1967).
[CrossRef]

Semeter, J. L.

J. L. Semeter, “Ground based tomography of atmoshperic optical emissions,” Ph.D. dissertation (Boston University, Boston, Mass., 1997).

Störmer, C.

C. Störmer, The Polar Aurora, Clarendon, Oxford, 1955.

Strickland, D. J.

D. J. Strickland, R. R. Meier, J. H. Hecht, A. B. Christensen, “Deducing composition and incident electron spectra from ground-based optical measurements: theory and model results,” J. Geophys. Res. 94, 13,527–13,539 (1989).
[CrossRef]

J. H. Hecht, A. B. Christensen, D. J. Strickland, R. R. Meier, “Deducing composition and incident electron spectra from ground-based auroral optical measurements: variations in oxygen density,” J. Geophys. Res. 94, 13,553–13,563 (1989).
[CrossRef]

Swenson, G. R.

S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
[CrossRef]

G. R. Swenson, S. B. Mende, K. S. Clifton, “Ram vehicle glow spectrum: implication of NO2 recombination continuum,” Geophys. Res. Lett. 12, 97–100 (1985).
[CrossRef]

R. Rairden, G. R. Swenson, “New imaging spectrometer for auroral research,” in Optical Spectroscopic Techniques and Instrumentation for Atmospheric and Space Research, J. Wang, P. B. Harp, eds., Proc. SPIE2266, 221–230 (1994).
[CrossRef]

Vickrey, J. F.

J. D. Kelly, C. J. Heinselman, J. F. Vickrey, R. R. Vondrak, “The Sondrestrom radar and accompanying ground-based instrumentation,” Space Sci. Rev. 71, 797–813 (1995).
[CrossRef]

Vondrak, R. R.

J. D. Kelly, C. J. Heinselman, J. F. Vickrey, R. R. Vondrak, “The Sondrestrom radar and accompanying ground-based instrumentation,” Space Sci. Rev. 71, 797–813 (1995).
[CrossRef]

Can. J. Phys. (2)

A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. II. The spectrum of medium intensity aurora between 4500 and 8900 Å,” Can. J. Phys. 52, 2343–2356 (1974).

A. V. Jones, R. L. Gattinger, “Quantitative spectroscopy of the aurora. III. The spectrum of medium intensity aurora between 3100 and 4700 Å,” Can. J. Phys. 53, 1806–1813 (1975).
[CrossRef]

Geophys. Res. Lett. (1)

G. R. Swenson, S. B. Mende, K. S. Clifton, “Ram vehicle glow spectrum: implication of NO2 recombination continuum,” Geophys. Res. Lett. 12, 97–100 (1985).
[CrossRef]

IEEE Proc. (1)

J. V. Evans, “Theory and practice of ionsphere study by Thomson scatter radar,” IEEE Proc. 57, 496–530 (1969).
[CrossRef]

J. Geophys. Res. (4)

J. H. Hecht, A. B. Christensen, D. J. Strickland, R. R. Meier, “Deducing composition and incident electron spectra from ground-based auroral optical measurements: variations in oxygen density,” J. Geophys. Res. 94, 13,553–13,563 (1989).
[CrossRef]

S. B. Mende, R. H. Eather, “Monochromatic all-sky observations and auroral precipitation patterns,” J. Geophys. Res. 81, 3771–3780 (1976).
[CrossRef]

M. H. Rees, D. Luckey, “Auroral electron energy derived from ratio of spectroscopic emissions. 1. Model computations,” J. Geophys. Res. 79, 5181–5186 (1974).
[CrossRef]

D. J. Strickland, R. R. Meier, J. H. Hecht, A. B. Christensen, “Deducing composition and incident electron spectra from ground-based optical measurements: theory and model results,” J. Geophys. Res. 94, 13,527–13,539 (1989).
[CrossRef]

J. Spacecr. Rockets (1)

S. B. Mende, G. R. Swenson, K. S. Clifton, R. Gause, L. Leger, O. K. Garriott, “Space vehicle glow measurements on STS-41D,” J. Spacecr. Rockets 23, 189–193 (1986).
[CrossRef]

Planet. Space Sci. (2)

J. G. Romick, A. E. Belon, “The spatial variation of auroral luminosity. II. Determination of volume emission rate profiles,” Planet. Space Sci. 15, 1695–1716 (1967).
[CrossRef]

M. H. Rees, “Auroral ionization and excitation by incident energetic electrons,” Planet. Space Sci. 11, 1209–1218 (1963).
[CrossRef]

Space Sci. Rev. (1)

J. D. Kelly, C. J. Heinselman, J. F. Vickrey, R. R. Vondrak, “The Sondrestrom radar and accompanying ground-based instrumentation,” Space Sci. Rev. 71, 797–813 (1995).
[CrossRef]

Other (4)

J. L. Semeter, “Ground based tomography of atmoshperic optical emissions,” Ph.D. dissertation (Boston University, Boston, Mass., 1997).

A. V. Jones, “Optical emissions from aurora,” in Aurora, Vol. 9 of Geophysics and Astrophysics Monograph (Reidel, Norwell, Mass., 1974), pp. 80–128.
[CrossRef]

C. Störmer, The Polar Aurora, Clarendon, Oxford, 1955.

R. Rairden, G. R. Swenson, “New imaging spectrometer for auroral research,” in Optical Spectroscopic Techniques and Instrumentation for Atmospheric and Space Research, J. Wang, P. B. Harp, eds., Proc. SPIE2266, 221–230 (1994).
[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 (17)

Fig. 1
Fig. 1

Illustration of the multiple spectroscopic study of auroral arcs. FOV, field of view.

Fig. 2
Fig. 2

(a) Geographic projection of the two stations used to study aurora arcs from Sondrestrom and Godhavn, Greenland. The labeled lines near Sondrestrom indicate the projection of a hypothetical auroral arc in the magnetic zenith of Sondrestrom at the indicated altitude in kilometers. (b) Same as (a) but a cross-sectional view for slant path viewing of auroral arcs from Godhavn to Sondrestrom. FOV, field of view; hv, high voltage.

Fig. 3
Fig. 3

Optical schematic of a f/1.4, CCD-based imaging spectrometer used to measure auroral spectra with high spatial and moderate spectral resolution.

Fig. 4
Fig. 4

Portion of the spectrum showing the spectral features of four emission lamps used to calibrate pixel versus wavelength for the Godhavn spectrometer.

Fig. 5
Fig. 5

(a) Wavelength versus the CCD column (pixel) for the Godhavn 1996 spectrometer. (b) The delta wavelength (or wavelength derivative) per column pixel versus wavelength (or pixel number).

Fig. 6
Fig. 6

Sequence of images used to generate a calibration image that converts counts per pixel to a brightness unit, R/pixel.

Fig. 7
Fig. 7

Plot of the column average signal from rows 58–68 in Fig. 6 (bottom).

Fig. 8
Fig. 8

Counts (per R pixel 30 s) for both the Godhavn and the Sondrestrom spectrometers.

Fig. 9
Fig. 9

Pair of raw images of auroral spectra acquired from the Godhavn spectra. The gray scale at the bottom of the figure was stretched to show faint source emissions, but otherwise is the same image as at the top of the figure. The angular projection of each row was referenced to an altitude by use of the geometry shown in Fig. 2(b), with an overlay of altitude contours for the arc as it was positioned over Sondrestrom.

Fig. 10
Fig. 10

Example of a raw image, after curvature of slit field correction is applied.

Fig. 11
Fig. 11

Three stacked keograms from the images acquired 23–24 March 1996 at Godhavn. The vertical dimension is angle (or altitude) along the slit, and the horizontal dimension represents time. The top, middle, and bottom keograms are acquired from row sums of columns indicated that represent the spectral regions for OI 557.7 nm (top), 630.0 nm (middle), and a relatively low-emission layer where stars are readily visible. Time is indicated in UT on the middle panel. On the left, sunset occurs as the bright Rayleigh-scattered sunlight disappears near 00 UT. Bright aurora is evident between 01:00 and 02:00 UT, but a weak red line (630.0) is prevalent throughout the rest of the night. The column numbered from left to right represents the numbered image acquired for the night, so column image reference is conveniently located with keograms.

Fig. 12
Fig. 12

Geometry of the projected slit of the Godhavn spectrometer on the Sondrestrom radar beam, with altitude limits set by the stop associated with the top and bottom of the slit. FWHP, full width at half-peak power.

Fig. 13
Fig. 13

Spectral image of an arc positioned over Sondrestrom as viewed from Godhavn, where the image was processed to convert the signal to R and was corrected for curvature. Altitude contours were superimposed (y axis) for the measured range of the arc and wavelength position (x axis). It is this form of the image in which spatial (altitude) and wavelength information are extracted and are analyzed through area integrations of the image.

Fig. 14
Fig. 14

Plot of intensity versus altitude for specific auroral features as described in Fig. 13. For all features, a column range is identified for a given wavelength band, and the rows are summed to yield the integral brightness. An identical column range is identified adjacent to the wavelength band of interest, similarly row summed, and subtracted for the calculated on-band emission brightness. The N2 1PG is a broad spectral region for which the background was not subtracted.

Fig. 15
Fig. 15

All-sky image of 4278-Å emission from Sondrestrom. This is shown for a time for the arc shown in Fig. 13, as observed with the spectrometer. The box fiducial in the field marks the pointing position of the ISR antenna, which took data simultaneously with the optical measurements, characterizing the ionosphere. The altitude distribution of electrons and the electron and ion temperatures were measured and included in the modeling of arc emissions.

Fig. 16
Fig. 16

Electron density and electron and ion temperatures on 15 March 1996 at 03:28 UT obtained from the Sondrestrom ISR. The radar was pointed along B (in the magnetic zenith) and operated in a mixed-pulse mode with 1-min integration times. Temperature-corrected electron densities were obtained by use of the method described in the text.

Fig. 17
Fig. 17

(a) Spectra taken along B of a soft arc (dashed curve) and hard arc (solid curve). The two spectra are normalized for energy flux (i.e., for the N2+ 4708 Å). (b) A plot of the difference between the two spectra shown in (a).

Equations (2)

Equations on this page are rendered with MathJax. Learn more.

N e = N r 2 1 + α 2 + T e T i 1 + α 2 ,
α 2 = 4 π D λ 2 = 1.43 × 10 7 T e N e .

Metrics