Ultraviolet Coronagraph Spectrometer for the Solar and Heliospheric Observatory: instrument description and calibration overview

The SOHO ultraviolet coronagraph spectrometer (UVCS/SOHO) is composed of three reflecting telescopes with external and internal occultation and a spectrometer assembly consisting of two toric grating spectrometers and a visible light polarimeter. The UVCS will perform ultraviolet spectroscopy and visible polarimetry to be combined with plasma diagnostic analysis techniques to provide detailed empirical descriptions of the extended solar corona from the coronal base to a heliographic height of 12 R. In this paper, the salient features of the design of the UVCS instrument are described. An overview of the UVCS test and calibration activities is presented. The results from the calibration activity have demonstrated that the UVCS can achieve all its primary scientific observational goals.