{'fraction_non_alphanumeric': 0.019784172661870502, 'fraction_numerical': 0.0035971223021582736, 'mean_word_length': 4.989247311827957, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Sensing systems for active control of the VLT

Each of the 12 Nasmyth and Cassegrain foci of the ESO very large telescope (VLT) will be equipped with an 'adapter/rotator' which provides the mechanical interface for the science instruments and several key functions for the control of the telescope, namely a CCD sensor for acquisition and guiding, and a separate CCD sensor as wavefront sensor for the active optics control system. This paper describes the origins and concept for the VLT adapter/rotators, and the principal design drivers and constraints.