The Large Angle Spectroscopic Coronagraph (LASCO)
Llebaria, A.; Michels, D. J.; Koomen, M. J.; Simnett, G. M.; Schwenn, R.; Lamy, P. L.; Bedford, D. K.; Howard, R. A.; Dere, K. P.; Korendyke, C. M.; Brueckner, G. E.; Moses, J. D.; Socker, D. G.; Eyles, C. J.; Bout, M. V.
United States, France, Germany, United Kingdom
Abstract
The Large Angle Spectroscopic Coronagraph (LASCO) is a three coronagraph package which has been jointly developed for the Solar and Heliospheric Observatory (SOHO) mission by the Naval Research Laboratory (USA), the Laboratoire d'Astronomie Spatiale (France), the Max-Planck-Institut für Aeronomie (Germany), and the University of Birmingham (UK). LASCO comprises three coronagraphs, C1, C2, and C3, that together image the solar corona from 1.1 to 30 R⊙ (C1: 1.1 - 3 R⊙, C2: 1.5 - 6 R⊙, and C3: 3.7 - 30 R⊙). The C1 coronagraph is a newly developed mirror version of the classic internally-occulted Lyot coronagraph, while the C2 and C3 coronagraphs are externally occulted instruments. High-resolution imaging spectroscopy of the corona from 1.1 to 3 R⊙ can be performed with the Fabry-Perot interferometer in C1. High-volume memories and a high-speed microprocessor enable extensive on-board image processing. Image compression by a factor of about 10 will result in the transmission of 10 full images per hour.