A concept is presented for a global network of robotically operated 2m-class telescopes, operating as a single globally
distributed observatory, for follow-up from the emerging generation of gigapixel focal plane survey telescopes and the
investigation of time-domain phenomena. The concept is developed from a model of approximately fifteen networked
telescopes of varying apertures and instrumentation compliments, and an exploration of the operating principles of the
network. A network architecture is presented which is able to deliver the remote operational support of this network. The
operating requirements of the unit telescope design are developed.
The Liverpool Telescope is a 2.0 metre robotic telescope that is operating unattended at the Observatorio del Roque de Los Muchachos, Spain. This paper gives an overview of the design and implementation of the telescope and its instrumentation and presents a snapshot of the current performance during the commissioning process. Science observations are under way, and we give brief highlights from a number of programmes that have been enabled by the robotic nature of the telescope.
The resolution of a conventional telescope is determined by the spatial extent of the collecting surface, usually the primary mirror. Astronomical interferometers achieve increased fine detail by using unit telescopes spaced over large distances to increase the spatial extent. The required wavefront quality places very tight tolerances on the unit telescopes and they should be designed with the prime goal of meeting the wavefront specification. The unit telescope must be optimized for the role of a beam compressor rather than attempting to modify a conventional design.
Two alternative designs that minimize the number of reflections in the telescope will be considered, a crucial feature in obtaining the lowest possible wavefront error and maximizing throughput. The first, a siderostat has fixed imaging optics and a large steerable flat mirror to enable sky tracking. The second, an "Alt-Alt" system consists of two intersecting altitude axes in a "gyroscopic type" structure. A small flat lies at the intersection of the altitude axes to direct the starlight at a constant height and direction out of the telescope. The benefits and limitations of each are shown along with the key design issues that determine the most appropriate unit telescope for implementation in an interferometric telescope.
As the latest generation of large (8 - 10 meter) telescopes are taking their first observations of our expanding universe, a new age of 2.0 m class high performance telescopes is emerging to support them. Telescopes of this aperture can be used as part of an interferometric array to combine their science beams with that of a larger telescope, as with the W. M. Keck and VLT Outrigger Telescopes projects. These telescopes are also used for survey and target acquisition work.
Telescope Technologies Limited have optimized the structural design of their range of 2.0 m telescopes for operation in the `open-air' during optical and near infra-red observations, in order to obtain the benefits of avoiding dome `seeing' and vibration effects from a rotating dome.
The Royal Greenwich Observatory and Liverpool John Moores University, United Kingdom, have joined in a collaboration to produce high quality, ground based robotic telescopes (2.0 to 5.0 m), for use with optical, infrared and interferometric astronomy. This venture has taken the form of a commercial company, Telescope Technologies Limited, to produce the range of Alt-azimuth telescopes. The reliability of the low cost, advanced technology, telescope design will enable remote observing over the Internet. The first two telescopes, currently under production, will see first light in La Palma and India in 1999. This paper covers the concept, design and capability range of the NGAT telescopes.