Abstract
The aim of this paper is to calculate an accurate large-scale flatfield for the STEREO HI-1 instruments. This is done by analysing the variation in intensity of stars in the background starfield as they pass across the CCD. In order to use the background starfield, a photometric calibration is performed which defines a HI magnitude scale and a conversion between this scale and measured intensity. The photometric calibration uses stellar spectra folded through the instrument response to make initial intensity predictions. However, a secondary prediction method based on the photometric calibration, which blends the R-, V- and B-magnitudes of a star, is derived for stars with no spectral information.
To perform this calibration, an initial analysis of the shape of the point spread function was required. This indicated that the PSF for the HI-1s is well approximated by a Gaussian function and does not vary substantially from the centre of the field-of-view to the corners and is essentially constant over time.
In addition, a solar spectrum folded through the instrument response is used to determine conversion factors to convert from HI intensity units into mean solar brightness, S10 and SI units, for diffuse or extended sources.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Brown, D.S., Bewsher, D., Eyles, C.J.: 2009, Solar Phys. 254, 185.
Brueckner, G.E., Howard, R.A., Koomen, M.J., Korendyke, C.J., Michels, D.J., Moses, J.D., Socker, D.G., Dere, K.P., Lamy, P.L., Llebaria, A., Bout, M.V., Schwenn, R., Simnett, G.M., Bedford, D.K., Eyles, C.J.: 1995, Solar Phys. 162, 357.
Buffington, A., Morrill, J.S., Hick, P.P., Howard, R.A., Jackson, B.V., Webb, D.F.: 2007, Proc. SPIE 6689. doi: 10.1117/12.734658 .
Cox, A.N. (ed.): 2000, Allen’s Astrophysical Quantities, 4th edn., Springer, Berlin.
Davis, C.J., Harrison, R.A.: 2005, Adv. Space Res. 36, 1524.
Eyles, C.J., Simnett, G.M., Cooke, M.P., Jackson, B.V., Buffington, A., Hick, P.P., Waltham, N.R., King, J.M., Anderson, P.A., Holladay, P.E.: 2003, Solar Phys. 217, 319.
Eyles, C.J., Harrison, R.A., Davis, C.J., Waltham, N.R., Shaughnessy, B.M., Mapson-Menard, H.C.A., Bewsher, D., Crothers, S.R., Davies, J.A., Simnett, G.M., Howard, R.A., Moses, J.D., Newmark, J.S., Socker, D.G., Halain, J.-P., Defise, J.-M., Mazy, E., Rochus, P.: 2009, Solar Phys. 254, 387.
Freeland, S.L., Handy, B.N.: 1998, Solar Phys. 182, 497.
Fulle, M., Leblanc, F., Harrison, R.A., Davis, C.J., Eyles, C.J., Halain, J.-P., Howard, R.A., Bockeleé-Morvan, D., Cremonese, G., Scarmato, T.: 2007, Astrophys. J. 661, L93.
Gray, D.: 1992, The Observation and Analysis of Stellar Photospheres, 2nd edn., Cambridge University Press, Cambridge.
Howard, R.A., Moses, J.D., Vourlidas, A., Newmark, J.S., Socker, D.G., Plunkett, S.P., Korendyke, C.M., Cook, J.W., Hurley, A., Davila, J.M., Thompson, W.T., St. Cyr, O.C., Mentzell, E., Mehalick, K., Lemen, J.R., Wuelser, J.P., Duncan, D.W., Tarbell, T.D., Wolfson, C.J., Moore, A., Harrison, R.A., Waltham, N.R., Lang, J., Davis, C.J., Eyles, C.J., Mapson-Menard, H., Simnett, G.M., Halain, J.P., Defise, J.M., Mazy, E., Rochus, P., Mercier, R., Ravet, M.F., Delmotte, F., Auchere, F., Delaboudiniere, J.P., Bothmer, V., Deutsch, W., Wang, D., Rich, N., Cooper, S., Stephens, V., Maahs, G., Baugh, R., McMullin, D., Carter, T.: 2008, Space Sci. Rev. 136, 67.
Jackson, B.V., Buffington, A., Hick, P.P., Altrock, R.C., Figueroa, S., Holladay, P.E., Johnston, J.C., Kahler, S.W., Mozer, J.B., Price, S., Radick, R.R., Sagalyn, R., Sinclair, D., Simnett, G.M., Eyles, C.J., Cooke, M.P., Tappin, S.J., Kuchar, T., Mizuno, D., Webb, D.F., Anderson, P.A., Keil, S.L., Gold, R.E., Waltham, N.R.: 2004, Solar Phys. 225, 177.
Kaiser, M.L., Kucera, T.A., Davila, J.M., St. Cyr, O.C., Guthathakurta, M., Christian, E.: 2008, Adv. Space Res. 136, 5.
Leinert, Ch., Bowyer, S., Haikala, L.K., Hanner, M.S., Hauser, M.G., Levasseur-Regourd, A.-Ch., Mann, I., Mattila, K., Reach, W.T., Schlosser, W., Staude, H.J., Toller, G.N., Weiland, J.L., Weinberg, J.L., Witt, A.N.: 1998, Astron. Astrophys. Suppl. 127, 1.
Morrill, J.S., Korendyke, C.M., Brueckner, G.E., Giovane, F., Howard, R.A., Koomen, M., Moses, D., Plunkett, S.P., Vourlidas, A., Esfandiari, E., Rich, N., Wang, D., Thernisien, A.F., Lamy, P., Llebaria, A., Biesecker, D., Michels, D., Gong, Q., Andrews, M.: 2006, Solar Phys. 233, 331.
Neckel, H., Labs, D.: 1984, Solar Phys. 90, 205.
Pickles, A.J.: 1998, Publ. Astron. Soc. Pac. 110, 749.
Rouillard, A.P., Davies, J.A., Forsyth, R.J., Davis, C.J., Harrison, R.A., Lockwood, M., Bewsher, D., Crothers, S.R., Eyles, C.J., Hapgood, M., Perry, C.H.: 2008, Geophys. Res. Lett. 35, L10110.
Sheeley, N.R. Jr., Herbst, A.D., Palatchi, C.A., Wang, Y.-M., Howard, R.A., Moses, J.D., Vourlidas, A., Newmark, J.S., Socker, D.G., Plunkett, S.P., Korendyke, C.M., Burlaga, L.F., Davila, J.M., Thompson, W.T., St. Cyr, O.C., Harrison, R.A., Davis, C.J., Eyles, C.J., Halain, J.P., Wang, D., Rich, N.B., Battams, K., Esfandiari, E., Stenborg, G.: 2008, Astrophys. J. 675, 853.
Stetson, P.B.: 1987, Publ. Astron. Soc. Pac. 99, 191.
Thernisien, A.F., Morrill, J.S., Howard, R.A., Wang, D.: 2006, Solar Phys. 233, 155. doi: 10.1007/s11207-006-2047-4 .
Thompson, W.T., Reginald, N.L.: 2008, Solar Phys. 250, 443. doi: 10.1007/s11207-008-9228-2 .
Tipler, P.A., Mosca, G.: 2004, Physics for Scientists and Engineers, 5th edn., Freeman, New York.
Vourlidas, A., Davis, C.J., Eyles, C.J., Crothers, S.R., Harrison, R.A., Howard, R.A., Moses, D.J., Socker, D.G.: 2007, Astrophys. J. 668, L79.
Webb, D.F., Mizuno, D.R., Buffington, A., Cooke, M.P., Eyles, C.J., Fry, C.D., Gentile, L.C., Hick, P.P., Holladay, P.E., Howard, T.A., Hewitt, J.G., Jackson, B.V., Johnston, J.C., Kuchar, T.A., Mozer, J.B., Price, S., Radick, R.R., Simnett, G.M., Tappin, S.J.: 2006, J. Geophys. Res. 111, A12101.
Zacharias, N., Monet, D.G., Levine, S.E., Urban, S.E., Gaume, R., Wycoff, G.L.: 2004, Bull. Am. Astron. Soc. 36, 1418.
Zeilik, M., Gregory, S.A., Smith, E.V.P.: 1992, Introductory Astronomy and Astrophysics, 3rd edn., p. 228, Saunders, Philadelphia.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Bewsher, D., Brown, D.S., Eyles, C.J. et al. Determination of the Photometric Calibration and Large-Scale Flatfield of the STEREO Heliospheric Imagers: I. HI-1. Sol Phys 264, 433–460 (2010). https://doi.org/10.1007/s11207-010-9582-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11207-010-9582-8