Data reduction and astrometric calibration of a starshade test using real starlight
Abstract
Calibration of data obtained during 2011-2013 for a ground-based optically scaled starshade alignment sensing test is discussed. The equipment included a 3.7-cm starshade-occulter in front of a coelostat at separations of up to 90-metres from a small telescope. Various stellar and planetary sources were observed. Astrometric reduction of images was challenged by variable horizontal refraction and wavefront distortion during occultations and between images which introduced uncertainty in localizing the occulter. Guider software issues were an additional complication in the reduction process and are discussed. The changing conditions during each observing session necessitate careful tagging of different datasets for appropriate treatment in the reduction pipeline. The techniques for handling the data are described along with astrometric results.
- Publication:
-
American Astronomical Society Meeting Abstracts #225
- Pub Date:
- January 2015
- Bibcode:
- 2015AAS...22542305J