A new high-order adaptive optics system is now being commissioned at the Lick Observatory Shane 3-meter telescope in California. This system uses a high return efficiency sodium beacon and a combination of low and high-order deformable mirrors to achieve diffraction-limited imaging over a wide spectrum of infrared science wavelengths covering 0.8 to 2.2 microns. We present the design performance goals and the first on-sky test results. We discuss several innovations that make this system a pathfinder for next generation AO systems. These include a unique woofer-tweeter control that provides full dynamic range correction from tip/tilt to 16 cycles, variable pupil sampling wavefront sensor, new enhanced silver coatings developed at UC Observatories that improve science and LGS throughput, and tight mechanical rigidity that enables a multi-hour diffraction-limited exposure in LGS mode for faint object spectroscopy science.
We describe the design and first-light early science performance of the Shane Adaptive optics infraRed Camera- Spectrograph (ShARCS) on Lick Observatory’s 3-m Shane telescope. Designed to work with the new ShaneAO adaptive optics system, ShARCS is capable of high-efficiency, diffraction-limited imaging and low-dispersion grism spectroscopy in J, H, and K-bands. ShARCS uses a HAWAII-2RG infrared detector, giving high quantum efficiency (<80%) and Nyquist sampling the diffraction limit in all three wavelength bands. The ShARCS instrument is also equipped for linear polarimetry and is sensitive down to 650 nm to support future visible-light adaptive optics capability. We report on the early science data taken during commissioning.
It is very common to write device drivers and code that access low level operation system functions in C or C+
+. There are also many powerful C and C++ libraries available for a variety of tasks. Java is a programming language
that is meant to be system independent and is arguably much simpler to code than C/C++. However, Java has minimal
support for talking to native libraries, which results in interesting challenges when using C/C++ libraries with Java code.
Part of the problem is that Java's standard mechanism for communicating with C libraries, Java Native Interface,
requires a significant amount of effort to do fairly simple things, such as copy structure data from C to a class in Java.
This is largely solved by using the Java Native Access Library, which provides a reasonable way of transferring data
between C structures and Java classes and calling C functions from Java. A more serious issue is that there is no
mechanism for a C/C++ library loaded by a Java program to call a Java function in the Java program, as this is a major
issue with any library that uses callback functions. A solution to this problem was found using a moderate amount of C
code and multiple threads in Java. The Keck Task Language API (KTL) is used as a primary means of inter-process
communication at Keck and Lick Observatory. KTL is implemented in a series or C libraries and uses callback functions
for asynchronous communication. It is a good demonstration of how to use a C library within a Java program.
Every bit of metadata added at the time of acquisition increases the
value of image data, facilitates automated processing of those data,
and decreases the effort required during subsequent data curation
In 2002 the FITS community completed a standard for World Coordinate
System (WCS) information which describes the celestial coordinates of
pixels in astronomical image data.
Most of the instruments in use at Lick Observatory and Keck Observatory
predate this standard.
None of them was designed to produce FITS files with celestial WCS information.
We report on the status of WCS keywords in the FITS files of
various astronomical detectors at Lick and Keck.
These keywords combine the information from sources which include the
telescope pointing system, the optics of the telescope and instrument,
a description of the pixel layout of the detector focal plane, and the
hardware and software mappings between the silicon pixels of the
detector and the pixels in the data array of the FITS file.
The existing WCS keywords include coordinates which refer to the
detector structure itself (for locating defects and artifacts), but
not celestial coordinates.
We also present proof-of-concept from the first data acquisition
system at Lick Observatory which inserts the WCS keywords for a
celestial coordinate system.
A successful instrument or telescope will measure its productive lifetime in decades;
over that period, the technology behind the control hardware and software will evolve, and be
replaced on a per-component basis. These new components must successfully integrate with
the old, and the difficulty of that integration depends strongly on the design decisions made
over the course of the facility's history. The same decisions impact the ultimate success of each
upgrade, as measured in terms of observing efficiency and maintenance cost.
We offer a case study of these critical design decisions, analyzing the layers of software
deployed for instruments under the care of UCO/Lick Observatory, including recent upgrades
to the Low Resolution Imaging Spectrometer (LRIS) at Keck Observatory in Hawaii, as well
as the Kast spectrograph, Lick Adaptive Optics system, and Hamilton spectrograph, all at Lick
Observatory's Shane 3-meter Telescope at Mt. Hamilton.
These issues play directly into design considerations for the software intended for use at
the next generation of telescopes, such as the Thirty Meter Telescope. We conduct our analysis
with the future of observational astronomy infrastructure firmly in mind.
Poco, short for Pointing Control, is a modern telescope control system for use with the telescopes at Lick
Observatory. It is currently in use with the Shane 3-meter and Nickel 1-meter telescopes. It may also be used with other
telescopes in the future. The software is designed to be very reliable, accurate, flexible, and full featured while still being
very easy to use. It needs to communicate with other systems such as auto-guiders, instruments, remote observing
watchdogs, and possible robotic control.
The telescopes use motor systems installed in the 1970's. Upgrading to modern servo motors was not practical,
so the telescopes use their stepper motors for fine motor control while switching to much larger and less accurate motors
for large moves. It requires a variety of techniques to quickly and smoothly reach target locations and maintain tracking.
The software achieves these goals, overcoming the significant hardware limitations of these older telescope
using mostly off the shelf hardware. This paper will describe the more interesting aspects of the system such as locating
objects from catalog coordinates, motor control algorithms, user interfaces, communications between systems, and
We describe a project to enable remote observing on the Nickel 1-meter Telescope at Lick Observatory. The purpose
was to increase the subscription rate and create more economical means for graduate- and undergraduate students to
observe with this telescope. The Nickel Telescope resides in a 125 year old dome on Mount Hamilton. Remote
observers may work from any of the University of California (UC) remote observing facilities that have been created to
support remote work at both Keck Observatory and Lick Observatory.
The project included hardware and software upgrades to enable computer control of all equipment that must be operated
by the astronomer; a remote observing architecture that is closely modeled on UCO/Lick's work to implement remote
observing between UC campuses and Keck Observatory; new policies to ensure safety of Observatory staff and
equipment, while ensuring that the telescope subsystems would be suitably configured for remote use; and new software
to enforce the safety-related policies.
The results increased the subscription rate from a few nights per month to nearly full subscription, and has spurred the
installation of remote observing sites at more UC campuses. Thanks to the increased automation and computer control,
local observing has also benefitted and is more efficient. Remote observing is now being implemented for the Shane 3-