Photoelectric Recording of Astronomical Seeing.
Abstract
An instrument has been built and tested for objectively and continuously monitoring the quality of astronomical seeing. A reticle in the form of a fine grid or lattice is placed at the focus of a small telescope, which is pointed at Polaris. Image tremor (imperfect seeing) causes fluctuations of the light passing the reticle and entering a photomultiplier, thus producing a Fourier frequency spectrum. (The component due to scintillation can be distinguished by occasional defocusing; it is generally of secondary importance.) The signal is analyzed with the aid of an ac amplifier, bandpass filter, rectifier, and recorder. Tests at Mount Wilson have shown that the instrument discriminates well among various grades of seeing, and that it can be calibrated by comparison with large telescopes.
- Publication:
-
The Astronomical Journal
- Pub Date:
- 1963
- DOI:
- 10.1086/109031
- Bibcode:
- 1963AJ.....68Q.272B