Improved Measurements of Scattered Light Level Behind Occulting Systems

摘要

The setup used to perform scattered-light intensity measurements behind different occulting systems, including a single disk, a toothed disc and new multi-thread occulter is described. The levels of scattered light are predicted using a formula adapted from the literature. Intensities theoretically calculated near the optical axis are compared with intensities measured with a pinhole photometer. The new multi-thread occulter is found to have excellent properties. Keywords: Coronagraph; External occulter; White light scattering; Reprints. (JHD)