19 research outputs found
AVIRIS ground data-processing system
The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has been under development at JPL for the past four years. During this time, a dedicated ground data-processing system has been designed and implemented to store and process the large amounts of data expected. This paper reviews the objectives of this ground data-processing system and describes the hardware. An outline of the data flow through the system is given, and the software and incorporated algorithms developed specifically for the systematic processing of AVIRIS data are described
ShaneAO: wide science spectrum adaptive optics system for the Lick Observatory
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.Comment: 11 pages, 10 figures. Presented at SPIE Astronomical Telescopes +
Instrumentation conference, paper 9148-7
Commissioning ShARCS: the Shane Adaptive optics infraRed Camera-Spectrograph for the Lick Observatory 3-m telescope
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.Comment: 9 pages, 7 figures. Presented at SPIE Astronomical Telescopes +
Instrumentation conference, paper 9148-11
Opto-Mechanical Design of ShaneAO: the Adaptive Optics System for the 3-meter Shane Telescope
A Cassegrain mounted adaptive optics instrument presents unique challenges
for opto-mechanical design. The flexure and temperature tolerances for
stability are tighter than those of seeing limited instruments. This criteria
requires particular attention to material properties and mounting techniques.
This paper addresses the mechanical designs developed to meet the optical
functional requirements. One of the key considerations was to have
gravitational deformations, which vary with telescope orientation, stay within
the optical error budget, or ensure that we can compensate with a steering
mirror by maintaining predictable elastic behavior. Here we look at several
cases where deformation is predicted with finite element analysis and Hertzian
deformation analysis and also tested. Techniques used to address thermal
deformation compensation without the use of low CTE materials will also be
discussed.Comment: 14 pages, 14 figures, 4 tables. Presented at SPIE Astronomical
Telescopes + Instrumentation conference, paper 9148-11
Update on the Preliminary Design of SCALES: the Santa Cruz Array of Lenslets for Exoplanet Spectroscopy
SCALES (Santa Cruz Array of Lenslets for Exoplanet Spectroscopy) is a 2-5
micron high-contrast lenslet integral-field spectrograph (IFS) driven by
exoplanet characterization science requirements and will operate at W. M. Keck
Observatory. Its fully cryogenic optical train uses a custom silicon lenslet
array, selectable coronagraphs, and dispersive prisms to carry out integral
field spectroscopy over a 2.2 arcsec field of view at Keck with low ()
spectral resolution. A small, dedicated section of the lenslet array feeds an
image slicer module that allows for medium spectral resolution (),
which has not been available at the diffraction limit with a coronagraphic
instrument before. Unlike previous IFS exoplanet instruments, SCALES is capable
of characterizing cold exoplanet and brown dwarf atmospheres ( K) at
bandpasses where these bodies emit most of their radiation while capturing
relevant molecular spectral features.Comment: 24 pages, 13 figures, SPIE Astronomical Instruments and Telescopes
2020 conferenc
The automated planet finder at Lick Observatory
By July 2014, the Automated Planet Finder (APF) at Lick Observatory on Mount Hamilton will have completed its first year of operation. This facility combines a modern 2.4m computer-controlled telescope with a flexible development environment that enables efficient use of the Levy Spectrometer for high cadence observations. The Levy provides both sub-meter per second radial velocity precision and high efficiency, with a peak total system throughput of 24%. The modern telescope combined with efficient spectrometer routinely yields over 100 observations of 40 stars in a single night, each of which has velocity errors of 0.7 to 1.4 meters per second, all with typical seeing of < 1 arc second full-width-half-maximum (FWHM). The whole observing process is automated using a common application programming interface (API) for inter-process communication which allows scripting to be done in a variety of languages (Python, Tcl, bash, csh, etc.) The flexibility and ease-of-use of the common API allowed the science teams to be directly involved in the automation of the observing process, ensuring that the facility met their requirements. Since November 2013, the APF has been routinely conducting autonomous observations without human intervention