OYSTER is the original interactive data reduction package developed for the Navy Prototype Optical Interferometer at Lowell (NPOI). It was created when three collections of scripts written first in PV-WAVE Command Language (PV-WAVE is a trademark of Visual Numerics, Inc.) and then also in the Interactive Data Language (IDL is a trademark of Research Systems Inc.) were merged into one for the purpose of providing a comprehensive data analysis package. The three original collections, CHAMELEON, which reduces a single night of data, AMOEBA, which fits models to the calibrated visibility data of several nights, and STARBASE, which implements a stellar data base and provides catalog access, are described in this User's Guide in separate parts. Also introduced are two new collections of scripts, COBRA, which provides functions for the interactive analysis of raw interferometry data (NPOI only), and PEARL, which images interferometry data.
The two versions of OYSTER which run under PV-WAVE CL and IDL are functionally identical1.1, but differ slightly in their widget layouts. As to the code, all of it with the exception of the widget code is compatible both with PV-WAVE CL and IDL. For reasons of simplification, we use IDL for all references to the language.
As of 2004, OYSTER is evolving to be of use for observations also of interferometers other than NPOI. This includes observation planning and data analysis. Reduction of data from other interferometers is not planned to be included in OYSTER since this involves obviously very instrument specific tasks.