| Autor: |
V.L. Buchholz, J. R. Auman, Gordon A. H. Walker, B. A. Goldberg, R. Knight, D. Wright, A. C. Gower, B.C. Isherwood |
| Rok vydání: |
1972 |
| Předmět: |
|
| DOI: |
10.1016/s0065-2539(08)60797-0 |
| Popis: |
Publisher Summary This chapter describes the application of an image isocon and computer to direct digitization of astronomical spectra. A system has been developed which uses a refrigerated image isocon as a detector for astronomical spectra. It is operated in the standard mode except that the reading beam can be left blanked for periods of up to 5 minutes. This allows a charge pattern to build up on the target at low light-levels. When the reading beam is unblanked, the target is scanned sequentially normal to the dispersion in 25 ms with a 680 line raster. In intermittent operation the frequency response characteristics of the amplifier are critically important if cross talk between spectral elements and also base-line distortions are to be minimized. There are a series of unevenly spaced nicks in the spectrum caused by over-discharging of the target during frame fly-back of the reading beam. The effect of poor low-frequency response of the amplifier has led to apparent shading of the continuum and base-line distortion. It is found that the immediate feedback to the observer has considerably improved the observing efficiency compared to photographic spectroscopy. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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