Hilton Lewis

The W. M. Keck Observatory Laser Guide Star Adaptive Optics System: Overview

The Keck Observatory began science observations with a laser guide star adaptive optics system, the first such system on an 8-10 m class telescope, in late 2004. This new capability greatly extends the scientific potential of the Keck II Telescope, allowing near-diffraction-limited observations in the near-infrared using natural guide stars as faint as 19th magnitude. This paper describes the conceptual approach and technical implementation followed for this system, including lessons learned, and provides an overview of the early science capabilities.

Advances in instrumentation at the W. M. Keck Observatory

In this paper we describe both recently completed instrumentation projects and our current development efforts in the context of the Observatorys science driven strategic plan which seeks to address key questions in observational astronomy for extra-galactic, Galactic, and planetary science with both seeing limited capabilities and high angular resolution adaptive optics capabilities. This paper will review recently completed projects as well as new instruments in development including MOSFIRE, a near IR multi-object spectrograph nearing completion, a new seeing limited integral field spectrograph for the visible wavelength range called the Keck Cosmic Web Imager, and the Keck Next Generation Adaptive Optics facility and its first light science instrument DAVINCI.

Experiments at the W.M. Keck Observatory to support the Thirty Meter Telescope design work

In order to validate various assumptions about the operating environment of the Thirty Meter Telescope (TMT), to validate the modeling packages being used to guide the design work for the TMT and to directly investigate the expected operation of several subsystems we have embarked on an extensive campaign of environmental measurements at the Keck telescopes. We have measured and characterized the vibration environment around the observatory floor and at certain locations on the telescope over a range of operating conditions. Similarly the acoustic environment around the telescope and primary mirror has been characterized for frequencies above 2 Hz. The internal and external wind and temperature fields are being measured using combined sonic anemometer and PRT sensors. We are measuring the telescope position error and drive torque signals in order to investigate the wind induced telescope motions. A scintillometer mounted on the telescope is measuring the optical turbulence inside the telescope tube. This experimental work is supplemented by an extensive analysis of telescope and engineering sensor log files and measurements, primarily those of accelerometers located on the main telescope optics, primary mirror segment edge sensor error signals (residuals), telescope structure temperature measurements and the telescope status information.

Do bigger telescopes need bigger software

We examine the factors that drive the size and cost of software for a hypothetical 30 meter telescope and compare those to that of a hypothetical 10 meter telescope. Our goal is to explore methods for developing estimates for such costs. The estimates provided here are intended primarily as examples for these methods, and should not be construed as accurate.

LUCIFER control software: an OO approach using CORBA technology

In this paper we present the design of the control software for the LBT NIR spectroscopic Utility with Camera and Integral- Field Unit for Extragalactic Research (LUCIFER) which is one of the first-light instruments for the Large Bin-ocular Telescope (LBT) on Mt. Graham, Arizona. The LBT will be equipped with two identical LUCIFER instruments for both mirrors. Furthermore we give an overview of the intended hardware structure of the instrument. Since the project requires a detailed and exact modeling of the software we present UML diagrams starting with an overall model down to use case, activity and class diagrams including an example for one special instrument unit

Pointing and tracking performance of the W.M. Keck Telescope

The achieved pointing and tracking performance of the telescope is presented and compared with the Keck goals. The implications of the current performance on observing are discussed, and planned remedies for deficiencies in pointing and tracking are proposed.

Detailed design of a deployable tertiary mirror for the Keck I telescope

Motivated by the ever increasing pursuit of science with the transient sky (dubbed Time Domain Astronomy or TDA), we are fabricating and will commission a new deployable tertiary mirror for the Keck I telescope (K1DM3) at the W.M. Keck Observatory. This paper presents the detailed design of K1DM3 with emphasis on the opto- mechanics. This project has presented several design challenges. Foremost are the competing requirements to avoid vignetting the light path when retracted against a sufficiently rigid system for high-precision and repeatable pointing. The design utilizes an actuated swing arm to retract the mirror or deploy it into a kinematic coupling. The K1DM3 project has also required the design and development of custom connections to provide power, communications, and compressed air to the system. This NSF-MRI funded project is planned to be commissioned in Spring 2017.

W. M. Keck Observatory operations

The operations model of the Keck Observatory and the factors that allow it to operate with unprecedented scientific success while maintaining the lowest operating cost to capital ratio of the 8m-10m class of telescopes are examined. We describe matching of resources to operating requirements and steps taken to optimize the effectiveness of the overall operation. We describe how strategic goals, operating philosophy and detailed planning mesh to match science objectives with technological capability. We conclude by examining how operations design drives both long term operating cost and realization of the potential inherent in the initial capital investment.

Keck II Telescope Control System

The experimental physics and industrial control system (EPICS) originated in the high energy physics community and has been used for several years to control accelerators. It is now in use or soon to be in use at several observatories around the world. In 1995, it was decided that Keck II telescope would have a new EPICS-based control system rather than use a copy of the Keck I system. This decision was made because it was felt that EPICS provided a superior software infrastructure to that developed for Keck I, and that it would scale well to encompass adaptive optics and eventual use of the two telescopes for interferometry. The new control system was developed throughout 1995 and the early part of 1996, leading to first light in January 1996, making it the first fully EPICS-controlled telescope control system in the world. This paper describes how EPICS has been used to implement the control system, including a detailed discussion of the axes control, pointing and timing system, and of how they interact with each other.

W.M. Keck Telescope control system

The computing environment and major components of the Keck telescope control system are discussed. This is followed by a discussion of calibration procedures and a review of current status and problems.