Hobby-Eberly Telescope Software Study
A software study for the upgrade of controls for the Hobby-Eberly telescope
by consultants from Observatory Sciences is part of a project to help our
understanding of the evolution of dark energy.
The Hobby-Eberly telescope (HET) was completed in 1997 as a joint project
of The University of Texas at Austin, The Pennsylvania State University,
Stanford University, Ludwig-Maximilians-Universität München, and
Georg-August-Universität Göttingen, and is based at the McDonald
Observatory in West Texas. Its design set a new paradigm for cost against performance, with the telescope marrying simple mechanical and optical construction principles with an innovative startracker mechanism, allowing overall costs to be dramatically reduced without any compromise in capability.
The telescope is a fixed elevation design with a large 11.1 x 9.8m primary
mirror, made up from 91 spherically shaped segments, giving it an effective
aperture of 9.2m. Elevation is fixed at 55°, so the primary mirror is
stationary with respect to gravity. The fixed elevation completely eliminates
the problem of variable distortion that affects traditional telescope
designs as their mount and optics are moved through all tilt angles
whilst aiming at different targets. It also dramatically simplifies the
telescope’s supporting framework, all of which significantly reduces cost.
The trade-off, however, was that a new solution was required for tracking
and there is restricted access to targets in the sky.
The solution for the HET had no precedent in a large optical telescope.
Objects are tracked by a moving instrument package located 13m above the
mirror at prime focus. As an object moves overhead, its light bounces off
the large stationary mirror, and the tracking package moves to catch it,
always precisely at the exact location of focus.
Now a major new project is planning to make use of the Hobby-Eberly
telescope. HETDEX (the Hobby-Eberly Telescope Dark Energy Experiment)
is a project designed to understand the evolutionary history of dark
energy, using the new VIRUS instrument installed for HETDEX.
The HETDEX experiment will require major upgrades to the hardware and
<< Back to Projects
software for the Hobby-Eberly Telescope and OSL, working with Patrick
Wallace from Tpoint Software, has provided a software study for the
upgraded telescope control system. The study was presented to the HETDEX Preliminary Design Review in April 2008. The proposal is to make use of the standard TPOINT software suite with the HET control system, despite the telescope’s design being radically different from other optical telescopes.