KEYWORDS: Data storage, Observatories, Data archive systems, Human-machine interfaces, Control systems, Device simulation, Telescopes, Thirty Meter Telescope, Data backup, Software development
The design and development of the TMT Software System is a complex, multi-year project that includes management, reviews, design work, and construction of software with a multi-organization team that spans three continents. The initial conceptual design was completed in 2014 and following multiple reviews, the construction phase began in 2017 with our India-based development partners. With completion of the TMT Common Software in 2019, construction development moved to the first phase of the Executive Software system, which was completed in late 2021. This paper describes the current state of the TMT Software System summarizing what has been accomplished to date and the next steps in design and development. Within the last year, TMT has become part of the larger USELT project, and this paper describes how this has influenced the software design and future development plans.
NIRSPEC is a high-resolution near-infrared echelle spectrograph on the Keck II telescope that was commissioned in 1999 and upgraded in 2018. This recent upgrade was aimed at improving the sensitivity and longevity of the instrument through the replacement of the spectrometer science detector (SPEC) and slit-viewing camera (SCAM). Commissioning began in 2018 December, producing the first on-sky images used in the characterization of the upgraded system. Through the use of photometry and spectroscopy of standard stars and internal calibration lamps, we assess the performance of the upgraded SPEC and SCAM detectors. First, we evaluate the gain, readnoise, dark current, and the charge persistence of the spec detector. We then characterize the newly upgraded spectrometer and the resulting improvements in sensitivity, including spectroscopic zero points, pixel scale, and resolving power across the spectrometer detector field. Finally, for SCAM, we present zero points, pixel scale, and provide a map of the geometric distortion of the camera.
IRIS (Infrared Imaging Spectrograph) is the near-infrared (0.84 to 2.4 micron) diffraction-limited imager and Integral Field Spectrograph (IFS) designed for the Thirty Meter Telescope (TMT) and the Narrow-Field Infrared Adaptive Optics System ( NFIRAOS ). The imager will have a 34 arcsec x 34 arcsec field of view with 4 milliarcseconds (mas) pixels. The IFS consists of a lenslet array and slicer, enabling four plate scales from 4 mas to 50 mas, with multiple gratings and filters. We will report the progress on the development of the IRIS Data Reduction System ( DRS ) in the final design phase. The IRIS DRS is being developed in Python with the software architecture based on the James Webb Space Telescope science calibration pipeline. We are developing a library of algorithms as individual Python classes that can be configured independently and bundled into pipelines. We will interface this with the observatory software to run online during observations and we will release the package publicly for scientists to develop custom analyses. It also includes a C library for readout processing to be used for both in real-time processing (e.g., up-the-ramp, MCDS) as well the ability for astronomers to use for offline reduction. Lastly, we will also discuss the development of the IRIS simulation packages that simulate raw spectra and image readout-data from the Hawaii-4RG detectors, which helps in developing reduction algorithms during this design phase.
The transition from construction to operations of the Thirty-Meter-Telescope (TMT) will happen over a phase of "early-operations” that will last several years to encompass the technical and science commissioning of its main systems, and will conclude when the facility enters "steady-state operations” (early 2030s according to the current schedule).
In this talk, we will present the current plan for technical and scientific operations of the Thirty-Meter-Telescope, including a description of its organizational structure, staffing and day-to-day activities. TMT's science operations model will be aimed at optimizing the science impact of the TMT and its operations efficiency, while providing a high-level of support to TMT users over all phases (submission, implementation and (post-)execution) of their science programs.
The Thirty Meter Telescope (TMT) is a massive international undertaking with a myriad of software packages delivered by partners around the world. A comprehensive software development process with a focus on quality assurance has been established and agreed to by the partners to ensure a consistent and well-integrated system. Additionally, thorough requirements verification is necessary to ensure the deliverables meet the needs and requirements of the observatory. As software engineering continues to progress, technologies such as cloud-based collaboration tools and automated testing through continuous integration systems have become common place and facilitate the development and verification processes. We describe how TMT leverages the use of modern software development tools and methodologies to promote a cohesive and complete software system, using the recent construction and delivery of TMT Common Software as an example.
The Thirty Meter Telescope (TMT) is a massive international undertaking with a myriad of software packages delivered by partners around the world. The Executive Software (ESW) package is the part of the TMT software system that is responsible for providing unified high-level control of observatory operations. It consists of five parts: a) a Sequencer Component that can be tailored to various sequencing needs by the loading of custom “scripts”, written in a TMT sequencing Domain Specific Language (DSL); b) a collection of these sequencing scripts used for critical observing tasks such as acquisition; c) user interface (UI) infrastructure that provides browser-based UI standards and access to TMT components and services; d) the set of UIs that observatory staff will use during operations to conduct TMT activities such as observing; and e) tools that assist in the visualization of observation data for quality assurance. In this paper, we describe the design of ESW, and give an update on the current status of the package, which is currently under construction.
The TMT Software System consists of software components that interact with one another through a software infrastructure called TMT Common Software (CSW). CSW defines the types of components in the software system and their functional roles, software services for integrating components, and library code that is used by developers to create the components and subsystems that make up the TMT Software System. The unique features of CSW include the use of multiple, open-source products as the basis of the services, and an approach that works to reduce the amount of CSW-produced infrastructure code. The core of CSW is implemented on the JVM in the Scala programming language with both Java and Scala programming interfaces as well as limited access from C/C++ and Python. The source code for CSW is open source and available on GitHub. TMT CSW has recently completed its construction phase and has been delivered to the project by our India partners. This paper summarizes the technical design, construction process, construction deliverables, changes in the design during implementation, and lessons learned.
NIRSPEC is a 1-5 um echelle spectrograph in use on the Keck II Telescope since 1999. The spectrograph is capable of both moderate (R=λ/▵λ~2000) and high (R~25,000) resolution observations and has been a workhorse instrument across many astronomical fields, from planetary science to extragalactic observations. In the latter half of 2018, we will upgrade NIRSPEC to improve the sensitivity and stability of the instrument and increase its lifetime. The major components of the upgrade include replacing the spectrometer and slit-viewing camera detectors with Teledyne H2RG arrays and replacing all transputer-based electronics. We present detailed design, testing, and analysis of the upgraded instrument, including the finalized optomechanical design of the new 1-5 μm slit-viewing camera, detector characterization of the science and Engineering A grade arrays, electronics systems, and updated software design. The optomechanical design of the slit-viewing camera and replacement detector head assembly have both been assembled and cold-tested in our lab. We also show results from the GigE interface to the SAM/ASIC boards to control the H2RG. The upgrade will continue NIRSPEC’s legacy as a powerful near-infrared spectrograph behind one of the world’s most scientifically productive telescopes.
Infrared Imaging Spectrograph (IRIS) is the first light instrument for the Thirty Meter Telescope (TMT) that consists of a near-infrared (0.84 to 2.4 micron) imager and integral field spectrograph (IFS) which operates at the diffraction-limit utilizing the Narrow-Field Infrared Adaptive Optics System (NFIRAOS). The imager will have a 34 arcsec x 34 arcsec field of view with 4 milliarcsecond (mas) pixels. The IFS consists of a lenslet array and slicer, enabling four plate scales from 4 mas to 50 mas, multiple gratings and filters, which in turn will operate hundreds of individual modes. IRIS, operating in concert with NFIRAOS will pose many challenges for the data reduction system (DRS). Here we present the updated design of the real-time and post-processing DRS. The DRS will support two modes of operation of IRIS: (1) writing the raw readouts sent from the detectors and performing the sampling on all of the readouts for a given exposure to create a raw science frame; and (2) reduction of data from the imager, lenslet array and slicer IFS. IRIS is planning to save the raw readouts for a given exposure to enable sophisticated processing capabilities to the end users, such as the ability to remove individual poor seeing readouts to improve signal-to-noise, or from advanced knowledge of the point spread function (PSF). The readout processor (ROP) is a key part of the IRIS DRS design for writing and sampling of the raw readouts into a raw science frame, which will be passed to the TMT data archive. We discuss the use of sub-arrays on the imager detectors for saturation/persistence mitigation, on-detector guide windows, and fast readout science cases (< 1 second).
With the successful completion of our preliminary design phase, we will present an update on all design aspects of the IRIS near-infrared integral field spectrograph and wide-field imager for the Thirty Meter Telescope (TMT). IRIS works with the Narrow Field Infrared Adaptive Optics System (NFIRAOS) to make observations at the diffraction limit of TMT at wavelengths between 0.84 and 2.4 microns. The imager has been expanded to a 34 arcsec field of view and the spectrograph has a wide range of filter and spectral format combinations with a contiguous field of view up to 112x128 spatial elements. Among the many challenges the instrument faces, and has tried to address in its design, are atmospheric dispersion up to 100 times the sampling scale, unprecedented saturation issues in crowded fields, and the need for integrated on-instrument wavefront sensors. But the scientific payoff is enormous and IRIS on TMT will open entirely new opportunities in all areas of astrophysical science.
Characterization of an instrument’s detector is an essential part of assessing the overall performance and ca- pabilities of an instrument. We present our efforts to characterize the HAWAII-2RG detector on the imager component of the OSIRIS instrument at W. M. Keck Observatory. In particular, we will report the detector’s read noise, dark current, linearity, and persistence. We find a gain of 2.16 ± 0.34, in good agreement with Teledyne’s reported gain of 2.15. The maximum read noise of the detector is 23.4 ± 1.3 e- decreasing with an increasing number of reads. We find an upper limit on the dark current of the detector to be < 0.021 e-/pix/s. The detector is also linear to the 1% level up to 44,500 e- and to the 5% level at 80,000 e-. The maximum well depth is measured to be 119,000 e-.
We present the results of the upgrade of the spectrograph detector in the integral field spectrograph, OSIRIS. OSIRIS is a near-infrared (1 to 2.5 microns) integral field spectrograph on the Keck I telescope. This instrument produces up to 3,000 spectra simultaneously over a contiguous rectangular field of view with a spectral resolution of ~3,800. OSIRIS works with the Keck Adaptive Optics system to achieve diffraction-limited spatial resolution and has four plate scales ranging from 0.02 to 0.10 arcseconds. At first light in 2005, the spectrograph portion of the instrument was equipped with a Rockwell Hawaii-2 detector. We have now upgraded this to a Teledyne Hawaii-2RG (H2RG) with lower read noise, lower dark current, and higher quantum efficiency. In addition to the upgraded detector, we also mounted the detector head on a linear stage, allowing the position of the detector to be accurately adjusted along the optical path when the instrument is at cryogenic temperatures (~80 K). This reduced the number of cool downs required to put the detector image plane at the spectrograph camera focus and adjust any residual tip/tilt of the detector image plane. We present the results of commissioning the new detector and the improved sensitivities of the OSIRIS instrument due to this upgrade.
IRIS is a near-infrared (0.84 to 2.4 micron) integral field spectrograph and wide-field imager being developed for first light with the Thirty Meter Telescope (TMT). It mounts to the advanced adaptive optics (AO) system NFIRAOS and has integrated on-instrument wavefront sensors (OIWFS) to achieve diffraction-limited spatial resolution at wavelengths longer than 1 μm. With moderate spectral resolution (R ~ 4000 – 8,000) and large bandpass over a continuous field of view, IRIS will open new opportunities in virtually every area of astrophysical science. It will be able to resolve surface features tens of kilometers across Titan, while also mapping the most distant galaxies at the scale of an individual star forming region. This paper summarizes the entire design and capabilities, and includes the results from the nearly completed preliminary design phase.
IRIS (InfraRed Imaging Spectrograph) is the diffraction-limited first light instrument for the Thirty Meter Telescope (TMT) that consists of a near-infrared (0.84 to 2.4 μm) imager and integral field spectrograph (IFS). The IFS makes use of a lenslet array and slicer for spatial sampling, which will be able to operate in 100’s of different modes, including a combination of four plate scales from 4 milliarcseconds (mas) to 50 mas with a large range of filters and gratings. The imager will have a field of view of 34×34 arcsec2 with a plate scale of 4 mas with many selectable filters. We present the preliminary design of the data reduction system (DRS) for IRIS that need to address all of these observing modes. Reduction of IRIS data will have unique challenges since it will provide real-time reduction and analysis of the imaging and spectroscopic data during observational sequences, as well as advanced post-processing algorithms. The DRS will support three basic modes of operation of IRIS; reducing data from the imager, the lenslet IFS, and slicer IFS. The DRS will be written in Python, making use of open-source astronomical packages available. In addition to real-time data reduction, the DRS will utilize real-time visualization tools, providing astronomers with up-to-date evaluation of the target acquisition and data quality. The quick look suite will include visualization tools for 1D, 2D, and 3D raw and reduced images. We discuss the overall requirements of the DRS and visualization tools, as well as necessary calibration data to achieve optimal data quality in order to exploit science cases across all cosmic distance scales.
The Multi-Object Spectrograph for Infrared Exploration (MOSFIRE) achieved first light on the W. M. Keck Observatory’s Keck I telescope on 4 April 2012 and quickly became the most popular Keck I instrument. One of the primary reasons for the instrument’s popularity is that it uses a configurable slitmask unit developed by the Centre Suisse d’Electronique et Microtechnique (CSEM SA) to isolate the light from up to 46 objects simultaneously. In collaboration with the instrument development team and CSEM engineers, the Keck observatory staff present how MOSFIRE is successfully used, and we identify what contributed to routine and trouble free nighttime operations.
The InfraRed Imaging Spectrograph (IRIS) will be a first-light client instrument for the Narrow Field Infrared Adaptive Optics System (NFIRAOS) on the Thirty Meter Telescope. IRIS includes three configurable tip/tilt (TT) or tip/tilt/focus (TTF) On-Instrument Wavefront Sensors (OIWFS). These sensors are positioned over natural guide star (NGS) asterisms using movable polar-coordinate pick-ofi arms (POA) that patrol an approximately 2-arcminute circular field-of-view (FOV). The POAs are capable of colliding with one another, so an algorithm for coordinated motion that avoids contact is required. We have adopted an approach in which arm motion is evaluated using the gradient descent of a scalar potential field that includes an attractive component towards the goal configuration (locations of target stars), and repulsive components to avoid obstacles (proximity to adjacent arms). The resulting vector field is further modified by adding a component transverse to the repulsive gradient to avoid problematic local minima in the potential. We present path planning simulations using this computationally inexpensive technique, which exhibit smooth and efficient trajectories.
The Thirty Meter Telescope (TMT) first light instrument IRIS (Infrared Imaging Spectrograph) will complete its preliminary design phase in 2016. The IRIS instrument design includes a near-infrared (0.85 - 2.4 micron) integral field spectrograph (IFS) and imager that are able to conduct simultaneous diffraction-limited observations behind the advanced adaptive optics system NFIRAOS. The IRIS science cases have continued to be developed and new science studies have been investigated to aid in technical performance and design requirements. In this development phase, the IRIS science team has paid particular attention to the selection of filters, gratings, sensitivities of the entire system, and science cases that will benefit from the parallel mode of the IFS and imaging camera. We present new science cases for IRIS using the latest end-to-end data simulator on the following topics: Solar System bodies, the Galactic center, active galactic nuclei (AGN), and distant gravitationally-lensed galaxies. We then briefly discuss the necessity of an advanced data management system and data reduction pipeline.
The Gemini Planet Imager (GPI) is a facility extreme-AO high-contrast instrument – optimized solely for study of faint companions – on the Gemini telescope. It combines a high-order MEMS AO system (1493 active actuators), an apodized pupil Lyot coronagraph, a high-accuracy IR post-coronagraph wavefront sensor, and a near-infrared integral field spectrograph. GPI incorporates several other novel features such as ultra-high quality optics, a spatially-filtered wavefront sensor, and new calibration techniques. GPI had first light in November 2013. This paper presnets results of first-light and performance verification and optimization and shows early science results including extrasolar planet spectra and polarimetric detection of the HR4696A disk. GPI is now achieving contrasts approaching 10-6 at 0.5” in 30 minute exposures.
We present an overview of the design of IRIS, an infrared (0.84 - 2.4 micron) integral field spectrograph and imaging
camera for the Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) and on-board wavefront
sensors, IRIS will take advantage of the high angular resolution of the narrow field infrared adaptive optics system
(NFIRAOS) to dissect the sky at the diffraction limit of the 30-meter aperture. With a primary spectral resolution of
4000 and spatial sampling starting at 4 milliarcseconds, the instrument will create an unparalleled ability to explore high
redshift galaxies, the Galactic center, star forming regions and virtually any astrophysical object. This paper summarizes
the entire design and basic capabilities. Among the design innovations is the combination of lenslet and slicer integral
field units, new 4Kx4k detectors, extremely precise atmospheric dispersion correction, infrared wavefront sensors, and a
very large vacuum cryogenic system.
KEYWORDS: IRIS Consortium, Galactic astronomy, Iterated function systems, Stars, Astronomy, Space telescopes, James Webb Space Telescope, Signal to noise ratio, Imaging systems, Spectroscopy
IRIS (InfraRed Imaging Spectrograph) is a first light near-infrared diffraction limited imager and integral field
spectrograph being designed for the future Thirty Meter Telescope (TMT). IRIS is optimized to perform astronomical
studies across a significant fraction of cosmic time, from our Solar System to distant newly formed galaxies (Barton et
al. [1]). We present a selection of the innovative science cases that are unique to IRIS in the era of upcoming space and
ground-based telescopes. We focus on integral field spectroscopy of directly imaged exoplanet atmospheres, probing
fundamental physics in the Galactic Center, measuring 104 to 1010 M supermassive black hole masses, resolved
spectroscopy of young star-forming galaxies (1 < z < 5) and first light galaxies (6 < z < 12), and resolved spectroscopy
of strong gravitational lensed sources to measure dark matter substructure. For each of these science cases we use the
IRIS simulator (Wright et al. [2], Do et al. [3]) to explore IRIS capabilities. To highlight the unique IRIS capabilities, we
also update the point and resolved source sensitivities for the integral field spectrograph (IFS) in all five broadband
filters (Z, Y, J, H, K) for the finest spatial scale of 0.004" per spaxel. We briefly discuss future development plans for the
data reduction pipeline and quicklook software for the IRIS instrument suite.
The Gemini Planet Imager (GPI) is a new facility instrument for the Gemini Observatory designed to provide direct detection and characterization of planets and debris disks around stars in the solar neighborhood. In addition to its extreme adaptive optics and coronagraphic systems which give access to high angular resolution and high-contrast imaging capabilities, GPI contains an integral field spectrograph providing low resolution spectroscopy across five bands between 0.95 and 2.5 μm. This paper describes the sequence of processing steps required for the spectro-photometric calibration of GPI science data, and the necessary calibration files. Based on calibration observations of the white dwarf HD 8049 B we estimate that the systematic error in spectra extracted from GPI observations is less than 5%. The flux ratio of the occulted star and fiducial satellite spots within coronagraphic GPI observations, required to estimate the magnitude difference between a target and any resolved companions, was measured in the H-band to be ∆m = 9.23 ± 0.06 in laboratory measurements and
∆m = 9.39 ± 0.11 using on-sky observations. Laboratory measurements for the Y, J , K1 and K2 filters are also presented. The total throughput of GPI, Gemini South and the atmosphere of the Earth was also measured in each photometric passband, with a typical throughput in H-band of 18% in the non-coronagraphic mode, with some variation observed over the six-month period for which observations were available. We also report ongoing development and improvement of the data cube extraction algorithm.
NIRSPEC is a high-resolution near-infrared (1-5 micron) echelle spectrometer in use on the Keck II telescope. We are
designing an upgrade to the spectrometer, and here we present modeling for the expected performance of the upgraded
system. The planned upgrade will (1) replace the Aladdin III science detector with a Teledyne H2RG, (2) update the slitviewing
camera (SCAM) detector to an H1RG and replace the optics, and (3) upgrade the instrument control
electronics. The new spectrometer detector has smaller pixels but a larger format, and its improved noise characteristics
will provide a dramatic increase in sensitivity, especially between OH lines in H-band and shorter wavelengths. Optical
modeling shows that the upgraded system is expected to achieve higher spectral resolution and a larger spectral grasp.
Also, preliminary modeling of the SCAM optical design aims to permit operation from 1-5 μm, overcoming a limitation
with the existing system.
The Gemini Planet Imager (GPI) is an “extreme” adaptive optics coronagraph system that is now on the
Gemini South telescope in Chile. This instrument is composed of three different systems that historically have
been separate instruments. These systems are the extreme Adaptive Optics system, with deformable mirrors,
including a high-order 64x64 element MEMS system; the Science Instrument, which is a near-infrared
integral field spectrograph; and the Calibration system, a precision IR wavefront sensor that also holds
key coronagraph components. Each system coordinates actions that require precise timing. The
observatory is responsible for starting these actions and has typically done this asynchronously across
independent systems. Despite this complexity we strived to provide an interface that is as close to a onebutton
approach as possible. This paper will describe the sequencing of these systems both internally and
externally through the observatory.
KEYWORDS: Sensors, Gemini Planet Imager, Calibration, Electroluminescent displays, Electrons, Gemini Observatory, Iterated function systems, Point spread functions, Signal to noise ratio, Data modeling
The Gemini Planet Imager is a newly commissioned facility instrument designed to measure the near-infrared spectra of young extrasolar planets in the solar neighborhood and obtain imaging polarimetry of circumstellar disks. GPI’s science instrument is an integral field spectrograph that utilizes a HAWAII-2RG detector with a SIDECAR ASIC readout system. This paper describes the detector characterization and calibrations performed by the GPI Data Reduction Pipeline to compensate for effects including bad/hot/cold pixels, persistence, non- linearity, vibration induced microphonics and correlated read noise.
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.
The Gemini Planet Imager (GPI) is a complex optical system designed to directly detect the self-emission of young
planets within two arcseconds of their host stars. After suppressing the starlight with an advanced AO system and
apodized coronagraph, the dominant residual contamination in the focal plane are speckles from the atmosphere and
optical surfaces. Since speckles are diffractive in nature their positions in the field are strongly wavelength dependent,
while an actual companion planet will remain at fixed separation. By comparing multiple images at different
wavelengths taken simultaneously, we can freeze the speckle pattern and extract the planet light adding an order of
magnitude of contrast. To achieve a bandpass of 20%, sufficient to perform speckle suppression, and to observe the
entire two arcsecond field of view at diffraction limited sampling, we designed and built an integral field spectrograph
with extremely low wavefront error and almost no chromatic aberration. The spectrograph is fully cryogenic and
operates in the wavelength range 1 to 2.4 microns with five selectable filters. A prism is used to produce a spectral
resolution of 45 in the primary detection band and maintain high throughput. Based on the OSIRIS spectrograph at
Keck, we selected to use a lenslet-based spectrograph to achieve an rms wavefront error of approximately 25 nm. Over
36,000 spectra are taken simultaneously and reassembled into image cubes that have roughly 192x192 spatial elements
and contain between 11 and 20 spectral channels. The primary dispersion prism can be replaced with a Wollaston prism
for dual polarization measurements. The spectrograph also has a pupil-viewing mode for alignment and calibration.
The growth of forest is critically vulnerable to the change in rainfall and radiation than in air temperature. The amount of rainfall and cloudiness in the northeast region of the United States is assumed to be strongly affected by the Atlantic sea surface temperature (SST). The observational investigation of the relation between the greenness of three undisturbed forested areas in the Atlantic region and Atlantic SST is fundamental to understand the response of terrestrial ecosystems to climate change. Such teleconnection signals may also entail the change of natural variability associated with several hydrological parameters such as rainfall and runoff. We conducted short-term environmental change quantification using MODIS satellite imageries supplemented by NEXRAD data. Wavelet analysis was employed to derive climate signals and embedded patterns over the timescale to illuminate the propagation effects of climate teleconnection.
This paper describes the as-built performance of MOSFIRE, the multi-object spectrometer and imager for the Cassegrain
focus of the 10-m Keck 1 telescope. MOSFIRE provides near-infrared (0.97 to 2.41 μm) multi-object spectroscopy over
a 6.1' x 6.1' field of view with a resolving power of R~3,500 for a 0.7" (0.508 mm) slit (2.9 pixels in the dispersion
direction), or imaging over a field of view of ~6.9' diameter with ~0.18" per pixel sampling. A single diffraction grating
can be set at two fixed angles, and order-sorting filters provide spectra that cover the K, H, J or Y bands by selecting 3rd,
4th, 5th or 6th order respectively. A folding flat following the field lens is equipped with piezo transducers to provide
tip/tilt control for flexure compensation at the <0.1 pixel level. Instead of fabricated focal plane masks requiring frequent
cryo-cycling of the instrument, MOSFIRE is equipped with a cryogenic Configurable Slit Unit (CSU) developed in
collaboration with the Swiss Center for Electronics and Microtechnology (CSEM). Under remote control the CSU can
form masks containing up to 46 slits with ~0.007-0.014" precision. Reconfiguration time is < 6 minutes. Slits are formed
by moving opposable bars from both sides of the focal plane. An individual slit has a length of 7.0" but bar positions can
be aligned to make longer slits in increments of 7.5". When masking bars are retracted from the field of view and the
grating is changed to a mirror, MOSFIRE becomes a wide-field imager. The detector is a 2K x 2K H2-RG HgCdTe
array from Teledyne Imaging Sensors with low dark current and low noise. Results from integration and commissioning
are presented.
The Gemini Planet Imager (GPI) is a new facility instrument for the Gemini Observatory designed to detect
and characterize planets and debris disks orbiting nearby stars; its science camera is a near infrared integral
field spectrograph. We have developed a data pipeline for this instrument, which will be made publicly available
to the community. The GPI data reduction pipeline (DRP) incorporates all necessary image reduction and
calibration steps for high contrast imaging in both the spectral and polarimetric modes, including datacube
generation, wavelength solution, astrometric and photometric calibrations, and speckle suppression via ADI and
SSDI algorithms. It is implemented in IDL as a flexible modular system, and includes both command line and
graphical interface tools including a customized viewer for GPI datacubes.
This GPI data reduction pipeline is currently working very well, and is in use daily processing data during
the instrument’s ongoing integration and test period at UC Santa Cruz. Here we summarize the results from
recent pipeline tests, and present reductions of instrument test data taken with GPI. We will continue to refine
and improve these tools throughout the rest of GPI’s testing and commissioning, and they will be released to the
community, including both IDL source code and compiled versions that can be used without an IDL license.
The Gemini Planet Imager is a next-generation instrument for the direct detection and characterization of young warm exoplanets, designed to be an order of magnitude more sensitive than existing facilities. It combines a 1700-actuator adaptive optics system, an apodized-pupil Lyot coronagraph, a precision interferometric infrared wavefront sensor, and a integral field spectrograph. All hardware and software subsystems are now complete and undergoing integration and test at UC Santa Cruz. We will present test results on each subsystem and the results of end-to-end testing. In laboratory testing, GPI has achieved a raw contrast (without post-processing) of 10-6 5σ at 0.4”, and with multiwavelength speckle suppression, 2x10-7 at the same separation.
MOSFIRE is a unique multi-object spectrometer and imager for the Cassegrain focus of the 10 m Keck 1 telescope. A
refractive optical design provides near-IR (0.97 to 2.45 μm) multi-object spectroscopy over a 6.14' x 6.14' field of view
with a resolving power of R~3,270 for a 0.7" slit width (2.9 pixels in the dispersion direction), or imaging over a field of
view of 6.8' diameter with 0.18" per pixel sampling. A single diffraction grating can be set at two fixed angles, and
order-sorting filters provide spectra that cover the K, H, J or Y bands by selecting 3rd, 4th, 5th or 6th order respectively. A
folding flat following the field lens is equipped with piezo transducers to provide tip/tilt control for flexure compensation
at the 0.1 pixel level. A special feature of MOSFIRE is that its multiplex advantage of up to 46 slits is achieved using a
cryogenic Configurable Slit Unit or CSU developed in collaboration with the Swiss Centre for Electronics and Micro
Technology (CSEM). The CSU is reconfigurable under remote control in less than 5 minutes without any thermal
cycling of the instrument. Slits are formed by moving opposable bars from both sides of the focal plane. An individual
slit has a length of 7.1" but bar positions can be aligned to make longer slits. When masking bars are removed to their
full extent and the grating is changed to a mirror, MOSFIRE becomes a wide-field imager. Using a single, ASIC-driven,
2K x 2K H2-RG HgCdTe array from Teledyne Imaging Sensors with exceptionally low dark current and low noise,
MOSFIRE will be extremely sensitive and ideal for a wide range of science applications. This paper describes the design
and testing of the instrument prior to delivery later in 2010.
The Gemini Planet Imager (GPI) is an "extreme" adaptive optics coronagraph system that will have the ability to directly
detect and characterize young Jovian-mass exoplanets. The design of this instrument involves eight principal institutions
geographically spread across North America, with four of those sites writing software that must run seamlessly together
while maintaining autonomous behaviour. The objective of the software teams is to provide Gemini with a unified
software system that not only performs well but also is easy to maintain. Issues such as autonomous behaviour in a
unified environment, common memory to share status and information, examples of how this is being implemented,
plans for early software integration and testing, command hierarchy, plans for common documentation and updates are
explored in this paper. The project completed its preliminary design phase in 2007, and has just recently completed its
critical design phase.
OSIRIS is an integral field infrared spectrograph designed for the Keck Adaptive Optics System. It utilizes an array of lenses and the latest infrared detector to simultaneously obtain more than 3000 spectra over a rectangular field of view (up to 48x64 spatial elements). In its broad band mode (16x64 spectra), each spectrum contains more than 1700 wavelength channels and covers an entire infrared band at a resolution of 3800. Due to the extremely low backgrounds between night sky lines and at AO spatial samplings, the instrument is also extremely sensitive. Here we present first results obtained during commissioning of the instrument following First Light in February 22, 2005. We demonstrate the performance of the instrument, in particular together with the Keck Observatory's adaptive optics system and provide a flavor of the science addressed with OSIRIS.
We present an overview of the OSIRIS integral field spectrograph which was recently commissioned on the Keck II Telescope. OSIRIS works with the Keck Adaptive Optics system and utilizes an infrared transmissive lenslet array to sample a rectangular field of view at close to the Keck diffraction limit. By packing the spectra close together (2 pixel rows per spectrum) and using the Rockwell Hawaii-2 detector (wavelengths between 1 and 2.5 microns), we achieve a relatively large field of view (up to 6."4) while maintaining full broad-band spectral coverage at a resolution of 3800. Among the challenges of the instrument are: a fully cryogenic design (approximately 250 kg are brought down to 55K); four spatial scales from 0."02 to 0."10; extremely low wavefront error (approximately 25 nm of non-common path error); large all aluminum optics for the spectrograph; extremely repeatable spectral formats; and a sophisticated data reduction pipeline. OSIRIS also serves as a starting point for our design of IRIS which is a planned integral field spectrograph for the Thirty Meter Telescope.
OSIRIS is a near infrared diffraction limited imaging field spectrograph under development for the Keck observatory adaptive optics system and scheduled for commissioning in fall 2004. Based upon lenslet pupil imaging, diffraction grating, and a 2Kx2K Hawaii2 HgCdTe array, OSIRIS is a highly efficient instrument at the forefront of today's technology. OSIRIS will deliver per readout up to 4096 diffraction limited spectra in a complex interleaved format, requiring new challenges to be met regarding user interaction and data reduction. A data reduction software package is under development, aiming to provide the observer with a facility instrument allowing him to concentrate on science rather than dealing with instrumental as well as telescope and atmosphere related effects. Together with OSIRIS, a pipeline for basic data reduction will be provided for a new Keck instrument for the first time. A status report is presented here together with some aspects of the data reduction pipeline.
OSIRIS is an infrared integral-field spectrograph built for the Keck AO system. Integral-field spectrographs produce very complicated raw data products, and OSIRIS is no exception. OSIRIS produces frames that contain up to 4096 interleaved spectra. In addition to the IFU capabilities of OSIRIS, the instrument is equipped with a parallel-field imager to monitor current AO conditions by imaging an off-axis star and evaluating its PSF. The design of the OSIRIS software was driven by the complexity of the instrument, switching the focus from simply controlling the instrument components to targeting the acquisition of usable scientific data.
OSIRIS software integrates the planning, execution, and reduction of observations. An innovation in the OSIRIS control software is the formulation of observations into 'datasets' rather than individual frames. Datasets are functional groups of frames organized by the needs and capabilities of the data reduction software (DRS). A typical OSIRIS dataset consists of dithered spectral observations, coupled with the associated imaging data from the parallel-field AO PSF imager. A Java-based planning tool enables 'sequences' of datasets to be planned and saved both prior to and during observing sessions. An execution client interprets these XML-based files, configures the hardware servers for both OSIRIS and AO, and executes the observations. The DRS, working on one dataset of raw data at a time, produces science-quality data that is ready for analysis. This methodology should lead to superior observational efficiency, decreased likelihood of observer error, minimized reduction time, and therefore, faster scientific discovery.
We present the design for a recently approved instrument for the Keck Telescope. Called OSIRIS, it was inspired by the optical spectrograph TIGER of R. Bacon et al. and will utilize an infrared transmissive lenslet array to sample a rectangular field of view at close to the Keck diffraction limit. By packing the spectra very closely together (2 pixel rows per spectrum) and using the Rockwell Hawaii-2 detector (wavelengths between 1 and 2.5 microns), we will achieve a relatively large field of view (up to 6."4) while maintaining full broad-band spectral coverage at a resolution of 3900. Due to the extremely low backgrounds between night sky lines and at AO spatial samplings, the instrument will reach point source sensitivities several times fainter than any existing infrared spectrograph. We are also coupling a separate infrared AO camera dubbed SHARC to work as an acquisition camera and to monitor the point spread function's behavior during long spectroscopic exposures. Among the challenges of the instrument are: a fully cryogenic design, four spatial resolutions from 0."02 to 0."10, large aluminum optics for the spectrography, extremely repeatable spectral formats and a sophisticated data reduction pipeline.
OSIRIS is a near infrared diffraction limited imaging field spectrometer under development for the Keck observatory adaptive optics system. Based upon lenslet pupil imaging, diffraction grating, and a 2K×2K Hawaii2 HgCdTe array, OSIRIS is a highly efficient instrument at the forefront of today’s technology. OSIRIS will deliver per readout up to 4096 diffraction limited spectra in a complex interleaved format, requiring new challenges to be met regarding user interaction and data reduction. A data reduction software package is under development, aiming to provide the observer with a facility instrument allowing him to concentrate on science rather than dealing with instrumental as well as telescope and atmosphere related effects. Together with OSIRIS, a pipeline for basic data reduction will be provided for a new Keck instrument for the first time. Some aspects of the data reduction pipeline will be presented here. The OSIRIS instrument as such, the astronomical background as well as other software tools were presented elsewhere on this conference.
OSIRIS is an infrared integral-field spectrograph being built for the Keck AO system. OSIRIS presents novel data reduction and user-interaction challenges which are addressed by software being developed for OSIRIS. The complex raw data frames, containing up to 4096 interleaved spectra, are reduced in real-time and meaningfully displayed for quality-of-observation feedback to observers. Following an observing night, data are optimally reduced to science-quality data cubes in a semi-automated fashion. Further, the software must efficiently coordinate OSIRIS' spectroscopic observations with the SHARC off-axis imager and the AO system.
To meet these demands, OSIRIS software is comprehensive and integrates the planning, execution, and reduction of observations. Facilitating this architecture is the formulation of observations into 'datasets', rather than into individual frames. Datasets are functional groups of frames organized by the needs and capabilities of the data reduction software (DRS). A typical dataset consists of dithered OSIRIS observations, coupled with associated off-axis AO PSF imagery from SHARC. A Java-based planning tool enables 'sequences' of datasets to be planned and saved both prior to and during observing sessions. An execution client interprets these XML-based files, and configures the hardware servers for OSIRIS, SHARC, and AO before executing the observations. As observations are completed, extensive information
about the instrument and observatory are collated in an archival relational database. The DRS then uses information in the database, as well as archived calibration data and SHARC PSF data to produce a final science-quality data product, which may include differential refraction corrections, 3D PSF modeling/deconvolution, and OH-suppression.
Developing state of the art instrumentation for astronomy is often best done by geographically disparate teams that span several institutions. These efforts necessarily require costly face-to-face meetings and site visits. The benefits of the World Wide Web, video conferencing, and modular design techniques, however, have recently increased the efficiency and lowered the costs of these efforts. In this paper we discuss how these methods were applied during the development an emerging collaboration to produce common detector systems
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