Abstract

Certain applications in imaging photometry and radiometry require a telescope–detector system with (preferably constant) response over a wide spectral range from the ultraviolet through the infrared. We describe the design and characterization of the Solar Bolometric Imager (SBI), a 30-cm-aperture Dall–Kirkham telescope combined with a gold-blacked, 80,000-element thermal array detector. Our SBI prototype provides spectrally uniform imaging in total solar light (0.28–2.6 µm) of heat-flow inhomogeneities at the solar photosphere, with better than 5-arc sec angular resolution over a 6.5 × 13 arc min field of view. A balloon-borne SBI would avoid most atmospheric transmission variation over this spectral range, enabling accurate study of the sources of total irradiance variation.

© 2001 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. C. Hanson, in Uncooled Infrared Imaging Arrays and Systems, P. Kruse, D. Skatrud, eds., Vol. 47 of Semiconductors and Semimetals Series (Academic, New York, 1997), Chap. 4, pp. 123–173.
  2. R. Wood, in Uncooled Infrared Imaging Arrays and Systems, P. Kruse, D. Skatrud, eds., Vol. 47 of Semiconductors and Semimetals Series (Academic, New York, 1997), Chap. 3, pp. 45–119.
  3. P. Foukal, J. Lean, “Magnetic modulation of solar luminosity by photospheric activity,” Astrophys. J. 328, 347–357 (1988).
    [CrossRef]
  4. R. Willson, H. Hudson, “Solar luminosity variations in solar cycle 21,” Nature 332, 810–812 (1988).
    [CrossRef]
  5. J. Hickey, B. Alton, H. Kyle, D. Hoyt, “Total solar irradiance measurements by ERB/Nimbus-7,” Space Sci. Rev. 48, 321–342 (1988).
  6. W. Chiang, L. Petro, P. Foukal, “A photometric search for solar giant convection cells,” Sol. Phys. 110, 129–138 (1987).
    [CrossRef]
  7. P. Foukal, J. Lean, “An empirical model of total solar irradiance variation between 1874–1988,” Science 247, 556–558 (1990).
    [CrossRef] [PubMed]
  8. P. Foukal, K. Harvey, F. Hill, “Do changes in the photospheric magnetic network cause the 11-yr variation of total solar irradiance?” Astrophys. J. Lett. 353, 712 (1990).
    [CrossRef]
  9. J. Lean, “Contribution of ultraviolet irradiance variations to changes in the sun’s total irradiance,” Science 244, 197–200 (1989).
    [CrossRef] [PubMed]
  10. D. Advena, V. Bly, J. Cox, “Deposition and characterization of far-infrared absorbing gold-blacking films,” Appl. Opt. 32, 1136–1144 (1993).
    [CrossRef] [PubMed]
  11. A. Cox, ed., Allen’s Astrophysical Quantities (Springer, New York, 2000), p. 367.
  12. L. Petro, P. Foukal, W. Rosen, R. Kurucz, K. Pierce, “A study of solar photospheric limb-darkening variations,” Astrophys. J. 283, 426–438 (1984).
    [CrossRef]

1993

1990

P. Foukal, J. Lean, “An empirical model of total solar irradiance variation between 1874–1988,” Science 247, 556–558 (1990).
[CrossRef] [PubMed]

P. Foukal, K. Harvey, F. Hill, “Do changes in the photospheric magnetic network cause the 11-yr variation of total solar irradiance?” Astrophys. J. Lett. 353, 712 (1990).
[CrossRef]

1989

J. Lean, “Contribution of ultraviolet irradiance variations to changes in the sun’s total irradiance,” Science 244, 197–200 (1989).
[CrossRef] [PubMed]

1988

P. Foukal, J. Lean, “Magnetic modulation of solar luminosity by photospheric activity,” Astrophys. J. 328, 347–357 (1988).
[CrossRef]

R. Willson, H. Hudson, “Solar luminosity variations in solar cycle 21,” Nature 332, 810–812 (1988).
[CrossRef]

J. Hickey, B. Alton, H. Kyle, D. Hoyt, “Total solar irradiance measurements by ERB/Nimbus-7,” Space Sci. Rev. 48, 321–342 (1988).

1987

W. Chiang, L. Petro, P. Foukal, “A photometric search for solar giant convection cells,” Sol. Phys. 110, 129–138 (1987).
[CrossRef]

1984

L. Petro, P. Foukal, W. Rosen, R. Kurucz, K. Pierce, “A study of solar photospheric limb-darkening variations,” Astrophys. J. 283, 426–438 (1984).
[CrossRef]

Advena, D.

Alton, B.

J. Hickey, B. Alton, H. Kyle, D. Hoyt, “Total solar irradiance measurements by ERB/Nimbus-7,” Space Sci. Rev. 48, 321–342 (1988).

Bly, V.

Chiang, W.

W. Chiang, L. Petro, P. Foukal, “A photometric search for solar giant convection cells,” Sol. Phys. 110, 129–138 (1987).
[CrossRef]

Cox, J.

Foukal, P.

P. Foukal, J. Lean, “An empirical model of total solar irradiance variation between 1874–1988,” Science 247, 556–558 (1990).
[CrossRef] [PubMed]

P. Foukal, K. Harvey, F. Hill, “Do changes in the photospheric magnetic network cause the 11-yr variation of total solar irradiance?” Astrophys. J. Lett. 353, 712 (1990).
[CrossRef]

P. Foukal, J. Lean, “Magnetic modulation of solar luminosity by photospheric activity,” Astrophys. J. 328, 347–357 (1988).
[CrossRef]

W. Chiang, L. Petro, P. Foukal, “A photometric search for solar giant convection cells,” Sol. Phys. 110, 129–138 (1987).
[CrossRef]

L. Petro, P. Foukal, W. Rosen, R. Kurucz, K. Pierce, “A study of solar photospheric limb-darkening variations,” Astrophys. J. 283, 426–438 (1984).
[CrossRef]

Hanson, C.

C. Hanson, in Uncooled Infrared Imaging Arrays and Systems, P. Kruse, D. Skatrud, eds., Vol. 47 of Semiconductors and Semimetals Series (Academic, New York, 1997), Chap. 4, pp. 123–173.

Harvey, K.

P. Foukal, K. Harvey, F. Hill, “Do changes in the photospheric magnetic network cause the 11-yr variation of total solar irradiance?” Astrophys. J. Lett. 353, 712 (1990).
[CrossRef]

Hickey, J.

J. Hickey, B. Alton, H. Kyle, D. Hoyt, “Total solar irradiance measurements by ERB/Nimbus-7,” Space Sci. Rev. 48, 321–342 (1988).

Hill, F.

P. Foukal, K. Harvey, F. Hill, “Do changes in the photospheric magnetic network cause the 11-yr variation of total solar irradiance?” Astrophys. J. Lett. 353, 712 (1990).
[CrossRef]

Hoyt, D.

J. Hickey, B. Alton, H. Kyle, D. Hoyt, “Total solar irradiance measurements by ERB/Nimbus-7,” Space Sci. Rev. 48, 321–342 (1988).

Hudson, H.

R. Willson, H. Hudson, “Solar luminosity variations in solar cycle 21,” Nature 332, 810–812 (1988).
[CrossRef]

Kurucz, R.

L. Petro, P. Foukal, W. Rosen, R. Kurucz, K. Pierce, “A study of solar photospheric limb-darkening variations,” Astrophys. J. 283, 426–438 (1984).
[CrossRef]

Kyle, H.

J. Hickey, B. Alton, H. Kyle, D. Hoyt, “Total solar irradiance measurements by ERB/Nimbus-7,” Space Sci. Rev. 48, 321–342 (1988).

Lean, J.

P. Foukal, J. Lean, “An empirical model of total solar irradiance variation between 1874–1988,” Science 247, 556–558 (1990).
[CrossRef] [PubMed]

J. Lean, “Contribution of ultraviolet irradiance variations to changes in the sun’s total irradiance,” Science 244, 197–200 (1989).
[CrossRef] [PubMed]

P. Foukal, J. Lean, “Magnetic modulation of solar luminosity by photospheric activity,” Astrophys. J. 328, 347–357 (1988).
[CrossRef]

Petro, L.

W. Chiang, L. Petro, P. Foukal, “A photometric search for solar giant convection cells,” Sol. Phys. 110, 129–138 (1987).
[CrossRef]

L. Petro, P. Foukal, W. Rosen, R. Kurucz, K. Pierce, “A study of solar photospheric limb-darkening variations,” Astrophys. J. 283, 426–438 (1984).
[CrossRef]

Pierce, K.

L. Petro, P. Foukal, W. Rosen, R. Kurucz, K. Pierce, “A study of solar photospheric limb-darkening variations,” Astrophys. J. 283, 426–438 (1984).
[CrossRef]

Rosen, W.

L. Petro, P. Foukal, W. Rosen, R. Kurucz, K. Pierce, “A study of solar photospheric limb-darkening variations,” Astrophys. J. 283, 426–438 (1984).
[CrossRef]

Willson, R.

R. Willson, H. Hudson, “Solar luminosity variations in solar cycle 21,” Nature 332, 810–812 (1988).
[CrossRef]

Wood, R.

R. Wood, in Uncooled Infrared Imaging Arrays and Systems, P. Kruse, D. Skatrud, eds., Vol. 47 of Semiconductors and Semimetals Series (Academic, New York, 1997), Chap. 3, pp. 45–119.

Appl. Opt.

Astrophys. J.

L. Petro, P. Foukal, W. Rosen, R. Kurucz, K. Pierce, “A study of solar photospheric limb-darkening variations,” Astrophys. J. 283, 426–438 (1984).
[CrossRef]

P. Foukal, J. Lean, “Magnetic modulation of solar luminosity by photospheric activity,” Astrophys. J. 328, 347–357 (1988).
[CrossRef]

Astrophys. J. Lett.

P. Foukal, K. Harvey, F. Hill, “Do changes in the photospheric magnetic network cause the 11-yr variation of total solar irradiance?” Astrophys. J. Lett. 353, 712 (1990).
[CrossRef]

Nature

R. Willson, H. Hudson, “Solar luminosity variations in solar cycle 21,” Nature 332, 810–812 (1988).
[CrossRef]

Science

J. Lean, “Contribution of ultraviolet irradiance variations to changes in the sun’s total irradiance,” Science 244, 197–200 (1989).
[CrossRef] [PubMed]

P. Foukal, J. Lean, “An empirical model of total solar irradiance variation between 1874–1988,” Science 247, 556–558 (1990).
[CrossRef] [PubMed]

Sol. Phys.

W. Chiang, L. Petro, P. Foukal, “A photometric search for solar giant convection cells,” Sol. Phys. 110, 129–138 (1987).
[CrossRef]

Space Sci. Rev.

J. Hickey, B. Alton, H. Kyle, D. Hoyt, “Total solar irradiance measurements by ERB/Nimbus-7,” Space Sci. Rev. 48, 321–342 (1988).

Other

C. Hanson, in Uncooled Infrared Imaging Arrays and Systems, P. Kruse, D. Skatrud, eds., Vol. 47 of Semiconductors and Semimetals Series (Academic, New York, 1997), Chap. 4, pp. 123–173.

R. Wood, in Uncooled Infrared Imaging Arrays and Systems, P. Kruse, D. Skatrud, eds., Vol. 47 of Semiconductors and Semimetals Series (Academic, New York, 1997), Chap. 3, pp. 45–119.

A. Cox, ed., Allen’s Astrophysical Quantities (Springer, New York, 2000), p. 367.

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 (9)

Fig. 1
Fig. 1

Overall schematic of the SBI telescope and system.

Fig. 2
Fig. 2

Net optical system transmission for the SBI, calculated from measured values for the individual components (two uncoated Pyrex mirrors, one ND 1.0 filter, and one fused-quartz detector window).

Fig. 3
Fig. 3

Gold-blacked Raytheon BST array of the kind used in the prototype SBI.

Fig. 4
Fig. 4

Percent spectral reflectance plot (diffuse + specular) for a gold-blackened BST detector array showing that approximately 99% of the incident light between 300 and 1600 nm is absorbed.

Fig. 5
Fig. 5

First solar images obtained with prototype SBI (a) at the solar limb and (b) near disk center.

Fig. 6
Fig. 6

Photometric scans (a) across limb faculae in Fig. 5(a) and (b) across a large sunspot in Fig. 5(b).

Fig. 7
Fig. 7

(a) Raw mean response (50 × 50 pixel box) as a function of lamp intensity is plotted both with the gold-blackened and unblackened arrays fully illuminated and with ∼1/3 of each array physically masked off to simulate observation of the solar limb. Also included are plots of the mean output level in the masked (dark) areas of both arrays showing the dark level shift discussed in the text. (b) More-detailed examination of the raw mean response as a function of lamp intensity for the gold-blackened array with masking and with the system gain optimized for the linear section of the response curve. Best line fits to the data are drawn through the points in all plots.

Fig. 8
Fig. 8

White-light image of lunar limb obtained with CCD camera and SBI telescope with relative intensity profile overlay, showing a scattering of 1.5% at 40 arc sec off the limb.

Fig. 9
Fig. 9

Wideband 160 × 320 flat-fielded image of a laboratory scene obtained with the SBI camera (top) shown with a 320 × 640 section of a 480 × 640 CCD image of the same scene for comparison (bottom).

Metrics