We present a conceptual design for a Precision Radial Velocity Spectrograph (PRVS) for the Gemini telescope. PRVS is
a fibre fed high resolving power (R~70,000 at 2.5 pixel sampling) cryogenic echelle spectrograph operating in the near
infrared (0.95 - 1.8 microns) and is designed to provide 1 m/s radial velocity measurements. We identify the various
error sources to overcome in order to the required stability. We have constructed models simulating likely candidates
and demonstrated the ability to recover exoplanetary RV signals in the infrared. PRVS should achieve a total RV error of
around 1 m/s on a typical M6V star. We use these results as an input to a simulated 5-year survey of nearby M stars.
Based on a scaling of optical results, such a survey has the sensitivity to detect several terrestrial mass planets in the
habitable zone around nearby stars. PRVS will thus test theoretical planet formation models, which predict an abundance
of terrestrial-mass planets around low-mass stars.We have conducted limited experiments with a brass-board instrument
on the Sun in the infrared to explore real-world issues achieving better than 10 m/s precision in single 10 s exposures and
better than 5 m/s when integrated across a minute of observing.
We report on the development of instrument concepts for a European ELT, expanding on studies carried out as part of the ESO OWL concept. A range of instruments were chosen to demonstrate how an ELT could meet or approach the goals generated by the OPTICON science team, and used to push the specifications and requirements of telescope and adaptive optics systems. Preliminary conclusions are presented, along with a plan for further more detailed instrument design and technology developments. This activity is supported by the European Community (Framework Programme 6, ELT Design Study, contract number 011863).
VISTA is a 4-m wide field survey telescope with a near infra-red camera and a demanding f/1 primary design now well into its manufacturing phase. We contracted out major items, and generated a coordinated approach to the management of engineering budgets through systems engineering, risks through risk management, and safety through the generation of safety cases. Control of the interfaces and science requirements has been maintained and developed through the current phase. The project is developing the commissioning plan to deliver an effective and safe facility. The current status of VISTA is presented as we move towards the on site integration phase.
Systems engineering as a discipline has been established for many years, being utilised to good effect most notably, in the defence industry. Its introduction in a formalised way to the UK ATC is relatively recent. Although a good start has been made in embedding the process within the lifecycle model, much work is still required to refine the systems engineering elements to cope with the complex (internationally collaborative) business model, the need to nurture creativity in the design process and the translation into a highly challenging cost-driven technology domain.
This paper explores the current status of systems engineering at the UK ATC, shows where further work is needed, and how improvements can be made to meet the challenges of next generation telescopes and instrumentation.
It is shown why the discipline is necessary, especially given that projects often comprise diverse global teams (both small and large), and it indicates the pitfalls of a tendency in the early stages of a project to focus on solutions rather than robust requirements capture.
Finally, despite the obvious value and yet often ill-understood rigours of system engineering, it is shown how innovation and creativity can be promoted rather than stifled.
Nowadays LZOS is carrying out work on the manufacturing of the M1 Mirror and M2 Mirror for the VISTA project (Visible and Infrared Survey Telescope for Astronomy) with the 4100mm diameter primary hyperbolic mirror with asphericity about 800 microns and the 1241mm diameter secondary hyperbolic mirror with asphericity about 350 microns. The current status of the work carried out is presented in the manuscript.
Nowadays LZOS is carrying out work on the manufacturing of the M1 Mirror and M2 Mirror for the VISTA project (Visible and Infrared Survey Telescope for Astronomy) with the 4100 mm diameter primary hyperbolic mirror with asphericity about 800 μmi and the 1241 mm diameter secondary hyperbolic mirror with asphericity about 350 μm. The current status of the work carried out is presented in the manuscript.
The high-performance nature of VISTA, the Visible & Infra-Red Survey Telescope for Astronomy, with its wide-field high-throughput f/1 optical design coupled with the multi-organisation, multi-disciplinary nature of the VISTA collaboration places significant demands on the project's Systems Engineering function. The project has relied heavily on a Systems Engineering approach, which has been vigorously applied throughout the conception, specification, and tendering stages of the project lifecycle, and is in place to be continued through the remaining phases of design & development, manufacture, assembly, commissioning, verification and acceptance.
As the project matures from the Requirements/Design phase towards the Development and Manufacturing phase, the current status of the VISTA project is illustrated in terms of its Systems Engineering aspects, along with examples of how a formal Systems Engineering approach has resulted in benefits to the important project parameters of performance, cost and schedule. Key tools such as engineering budgets, configuration control procedures and the approach to risk management will be discussed in terms of their value to the project.
Systems Engineering has been used throughout the development of the Visible and Infrared Survey Telescope for Astronomy (VISTA). VISTA was originally conceived as being a classic 4m telescope with wide-field imaging capability. The UK Astronomy Technology Centre (UK ATC) radically changed this thinking by treating the whole design as one system, integrating the camera optics into the telescope design.
To maximise the performance, an f/1 primary mirror was adopted resulting in a very compact telescope and enclosure. Amongst other benefits, this reduced the overall mass of the telescope from 250 to 90 tonnes. During this optimisation process, the concept of a direct imaging K-short camera was developed. This development, in conjunction with an increase in IR field of view, produced a system with uniform image quality and throughput across a 350 mm diameter focal plane, 1.65 degree field.
While this has presented some major engineering challenges, the approach has produced a system which is both scientifically rewarding and achievable. The optimisation, design trade-offs and Technical Specification developed in the conceptual design phase were achieved through a systems analysis approach.
This paper describes some of the key systems engineering decisions and the tools employed to achieve them. Current systems engineering activities are described and future plans outlined.
This paper describes the conceptual design for a near infrared camera for the Visible and Infrared Survey Telescope for Astronomy (VISTA). VISTA is a 4m class survey telescope that is being designed to perform pre-planned, ground-based astronomical surveys of the Southern sky from ESO's Cerro Paranal Observatory in Chile. The IR Surveys will be carried out in the J, H and K<sub>short</sub> wave-bands at fainter magnitudes than those produced by the current generation of survey telescopes. To maximise throughput and survey efficiency, the camera has been completely integrated with the overall optical design with the telescope mirrors providing the power and the camera optics the wavefront correction. The camera design employs a non-traditional approach to control stray light by using cryogenic baffles rather than the more traditional cold-stop approach. The very large optical field available, 1.6° diameter with a plate scale of approximately 57μm/arcsec, means that the focal plane can accommodate sixteen 2k×2k IR detectors thus forming the largest IR focal plane used in ground based astronomy to date. The 67 Mpixel focal plane will generate a significant data rate. Each exposure will comprise 270 MB and a typical night will generate 400 GB.