Development of SQUEAN software system (SED camera for the QUasars in EArly uNiverse)

Spectral energy distribution (SED) camera for QUasars in EArly uNiverse (SQUEAN) has been developed and operated at the 2.1 m Otto Struve Telescope in the McDonald Observatory, US, since 2015 February. SQUEAN can have up to 20 medium band filters to measure SEDs of high redshift quasar candidates (z >5), gamma ray bursts, supernova, asteroids, etc. In the development process of the SQUEAN control software, we applied the spiral model, in which the software evolves by the repetition of every systemic process. The SQUEAN control software consists of the SQUEAN Main Observation Package (SMOP), the Kyung Hee University (KHU) Filter wheel Control Package for the McDonald Observatory 82 inch (or 2.1 m) telescope (KFC82), and the KHU Autoguiding Package (KAP82). The SMOP takes science data with various readout modes such as open shutter mode, semi-auto-focus mode, and script mode. The KFC82 controls the filter wheel with medium bands by network communications through the SMOP. The KAP82 monitors a reference star and auto-guides the telescope during observations.