The Huntsman Telescope: lessons learned from building an autonomous telescope from COTS components

Abstract

The Huntsman Telescope* is a wide field imager based on the successful Dragonfly Telescope concept.(1) It consists of an array of co-aligned telephoto DSLR lenses with cooled CCD cameras. The ten 140 mm apertures have a combined collecting area equivalent to a 0.5 m class telescope but have lower stray light levels than a typical telescope of this size.(1, 2) Its primary purpose is low surface brightness imaging of nearby galaxies, and it also observes exoplanet transits and other optical transients [GRAPHICS] A notable aspect of the design is that it is almost entirely assembled from commercial off-the-shelf (COTS) components. While this approach reduces design effort and raw hardware costs, integrating a disparate collection of COTS components into a reliable autonomous instrument presents its own set of challenges, particularly in relation to control. Huntsman uses control software based on Project PANOPTES',(dagger) POCS. POCS double dagger is a modular observatory automation library based on a state machine architecture. We have contributed additional hardware support to POCS, and made addatiorrs to the state machine and scheduler to support Hinitsman observing [GRAPHICS] modes. The large number of USB devices necessitated the implementation of a distributed control system, which we achieved using inexpensive commodity hardware (Raspberry Pis). The array configuration of Huntsman lends itself to instrumentation experiments. During commissioning we have performed simultaneous side-by-side comparisons of the DSLR. lenses with a Rowe-Ackerman Schmidt Astrograph (see Figure 2), and between two types of CCD cameras. We also have plans to test CMOS image sensor cameras and engineered diffusers for transit observations. Show more