Data Analysis Procedures for the International Ultraviolet Explorer Regional Data Analysis Facilities, Part I: Guidelines for Determining the Wavelengths and Fluxes from Extracted Spectra

The reduction of data from the International Ultraviolet Explorer (IUE) is a complicated and involved process. Fortunately, the majority of the reduction process is performed by the International Ultraviolet Explorer Spectral Image Processing System (IUESIPS). However, since this system is designed to reduce all of the IUE data, the accuracy of the results can be improved by tailored processing for each specific observation. This document addresses the limitations imposed by the IUESIPS design which can be improved by tailored processing beyond that done by IUESIPS. Three areas are discussed: Wavelengths, fluxes, and signal-to-noise ratios. In each area, a method for analyzing the IUESIPS processing is presented; factors which effect the accuracy are discussed; methods for correcting common problems are derived; and the accuracy limitations of IUE data are addressed.