Calibration and Processing of EUVE Spectrometer Observations

The Extreme Ultraviolet Explorer (EUVE) Guest Observer program, which began on January 22, 1993, consists of pointed observations with the EUVE spectrometers. These instruments, which cover the 70--760 Angstroms band in three overlapping channels, are calibrated with data taken on the ground prior to launch and with in-orbit observations of targets. In this poster we discuss the latest results from this calibration effort, illustrated by the in-orbit calibration observations. The best current wavelength solutions, derived from observations of stellar emission line sources, and instrument throughputs, calibrated with observations of EUV continuum sources, are presented, along with measurements of the resolution and throughput stability of the spectrometers. Issues under investigation are also discussed; these include digitization effects in the data processing, correction for deadtime in the instruments and overflow of telemetry slots, recovery of unreported aspect variation, and correction of small-scale distortions in the detectors. The current understanding of these issues and their effect on EUVE observations is presented. This work has been supported by NASA contract NAS5-30180.