KEYWORDS: Telescopes, Equipment, Observatories, Information operations, Robotics, Software development, Control systems, Control software, Computer architecture
The Intelligent Observatory (IO) is a project of the South African Astronomical Observatory which aims to improve the efficiency of observing, optimize the use of the observatory’s resources and allow rapid follow-up of targets of interest. We have developed software to enable our telescopes and instruments to be programmatically controlled and have used this to develop remotely operable web interfaces for each of these. We are now focused on enabling robotic operation. To this end we have adopted the Las Cumbres Observatory’s Observatory Control System (OCS). This allows users to submit observing requests, and the OCS scheduler produces a schedule of observations for each telescope. We have developed software to retrieve the latest schedule, configure the telescope and instruments accordingly, and take the required exposures. In full robotic mode, it is important that the telescopes and instruments be operated only when safe to do so. We have developed watchdog software, using the same interfaces, to monitor the weather and shut down telescopes and instruments if the weather turns bad.
South African Astronomical Observatory has been spearheading an effort to modernize the optical/IR observing facilities in the country and also from across the African continents to network them to form an Intelligent Observatory (IO), operating robotically from a centralized control brain. To achieve such an ambitious system, one need to be equipped with modern technologies, computation capabilities, real-time coordination between observers and observatory, autonomous trigger management system etc. The primary objective is to enable a comprehensive facility for the follow up observations triggered by the most sophisticated global facilities like LSST, ROMAN, zTF, CTA etc. in near future. The recent developments at SAAO, the Observatory Control System (OCS) has proven to be an integrated sub-component of the complex IO architecture. The OCS, because of a simplistic fragmentation in terms of the definitions of the various components: such as telescopes, instruments, observations, logging; helped the IO architecture uniquely to integrate very old telescope and instruments, originally not designed for the automated operations. The OCS has reduced a lot of burden of the observatory management team by providing a communicable database for managements and data visualization.
In the operation of robotic telescopes, ensuring equipment protection from adverse weather conditions and avoiding unproductive observations during heavy cloud cover are essential. Traditional methods of monitoring the sky for cloud typically involve IR cloud sensors that are prone to degradation and require regular calibration to provide reliable data. To address this, we propose a more sophisticated and reliable approach: comparing real-time zero-point values from astrometrically and photometrically calibrated all-sky images, provided by the ATLAS project, with a master reference zero-point map captured by the same system under ideal cloudless conditions to conduct a spatially resolved assessment of cloud cover across the entire visible sky. Currently, this method guides a basic decision of whether to observe or not. However, in the future, a more sophisticated approach could determine which sections of the sky are suitable for observation and limit observation requests to those specific areas.
The South African Astronomical Observatory (SAAO) has launched a strategic upgrade program named the Intelligent Observatory (IO), aiming to advance SAAO into the so-called fourth industrial revolution. Over the past two years, this initiative has achieved a significant milestone: all three of SAAO’s primary telescopes have been upgraded to support remote operations from anywhere in the world, with one telescope now fully automated. This enhancement in operational capabilities significantly bolsters support for all scientific endeavors, especially in the domains of transient and time-domain science, the core focus areas of the IO. Moreover, these upgrades open new avenues for synergistic integration with other hosted telescopes on the Sutherland plateau, as well as with additional ground-based and space-based observatories. In our ongoing quest for efficiency and responsiveness, we are developing sophisticated algorithms capable of adapting observational strategies in real-time based on dynamic weather patterns. Additionally, the creation of a comprehensive science archive is underway, which will offer fully reduced data products from all telescopes and instruments.
The South African Astronomical Observatory’s (SAAO’s) “Intelligent Observatory” (IO) project is an initiative that aims to future-proof and strategically position the SAAO as a follow-up characterisation “machine” for transient alerts using the diverse facilities owned and hosted by the observatory. We present an overview of the many facilities available at the SAAO, with a particular emphasis on the new and upgraded facilities tailored towards autonomous rapid-response observing. Additionally, we delve into some of the scientific programs that currently leverage these new capabilities.
We present Mookodi (meaning “rainbow” in Sesotho), a multipurpose instrument with a low-resolution spectrograph mode and a multi-filter imaging mode for quick-reaction astronomical observations. The instrument, mounted on the 1-m Lesedi telescope at the South African Astronomical Observatory in Sutherland (South Africa), is based on the low-resolution spectrograph for the rapid acquisition of transients (SPRAT) instrument in operation on the 2-m Liverpool Telescope in La Palma (Canary Islands, Spain). Similar to SPRAT, Mookodi has a resolution R≈350 and an operating wavelength range in the visible (∼4000 to 8000 Å). The linear optical design, as in SPRAT, is made possible through the combination of a volume phase holographic transmission grating as the dispersive element and a prism pair (grism), which makes it possible to rapidly and seamlessly switch to an imaging mode by pneumatically removing the slit and grism from the beam and using the same detector as in spectrographic mode to image the sky. This imaging mode is used for auto-target acquisition, but the inclusion of filter slides in Mookodi’s design also provides the capability to perform imaging with a field-of-view ≈10′×10′ (∼0.6″/px) in the complete Sloan Digital Sky Survey filter set.
We describe the software architecture of the Local Control Units (LCU) being deployed as part of the Intelligent Observatory project of the South African Astronomical Observatory. This is an integrated system for scheduling and controlling observations across several telescopes and instruments. As part of this, each telescope and its associated instruments fall under the control of an LCU. The LCU interfaces with the observatory-wide scheduler, executing observations as requested. It also monitors observing conditions and shuts down the telescope if necessary. The software is layered, modular and distributed, and allows remote and robotic control of the various instruments and telescopes.
We present an overview of the Intelligent Observatory (IO) and the architecture used at the South African Astronomical Observatory (SAAO) to develop instrument and telescope control and monitoring software. The IO aims to link and coordinate the usage of the SAAO telescopes and instruments for optimal efficiency. This will entail a Central Control System (CCS) selecting appropriate instruments and telescopes and controlling observations on these. This requires interoperable instrument and telescope control software. The SAAO software architecture is flexible, allows multiple user interfaces, and supports remote control and monitoring of both telescope and instrument through a web browser. Furthermore, the architecture allows an external agent (such as the IO CCS) simultaneous control of both instruments and telescopes.
We report on the extensively upgraded Cassegrain spectrograph on the South African Astronomical Observatory (SAAO) 1.9-m telescope. The introduction of new collimator and camera optics, a new detector and controller, a rear-of-slit viewing camera to facilitate acquisition, and a new instrument control and quick-look data-reduction software (to take advantage of the entire system now being governed by a programmable logic controller) has revolutionized this workhorse instrument on Africa’s second largest optical telescope. The improvement in throughput over the previous incarnation of the spectrograph is ∼50 % in the red, increasing to a factor of four at the blue end. A selection of 10 surface-relief diffraction gratings is available to users, offering a variety of wavelength ranges and resolutions, with resolving powers between ∼500 and 6500. SpUpNIC (Spectrograph Upgrade: Newly Improved Cassegrain) has been scheduled for ∼80 % of the time available on the 1.9-m since being installed on the telescope in late October 2015, providing the single-object spectroscopic capability to support the broad research interests of the SAAO’s local and international user community. We present an assortment of data obtained for various observing programs to demonstrate different aspects of the instrument’s enhanced performance following this comprehensive upgrade.
The South African Astronomical Observatory (SAAO) is currently developing WiNCam, the Wide-field Nasmyth Camera, to be mounted on Lesedi, the observatory’s new 1-metre telescope. This paper discusses the design and results for the remotely-operated camera system. The camera consists of an E2V-231-C6 Back Illuminated Scientific Charge Coupled Device (CCD) sensor with 6144x6160 pixels, four outputs operating in non-inverted mode. This is to date the largest single chip CCD-system developed at SAAO. The CCD is controlled with a modified Inter-University Centre for Astronomy and Astrophysics (IUCAA) Digital Sampler Array Controller (IDSAC) utilizing digital correlated double sampling. The camera system will have full-frame and frame-transfer read out modes available with sub-windowing and pre-binning abilities. Vacuum through-wall PCB technology is used to route signals through the vacuum interface between the controller and the CCD. A thin, compact, 125x125mm aperture, sliding-curtain-mechanism shutter was designed and manufactured together with a saddle-type filter-magazine-gripper system. The CCD is cryogenically cooled using a Stirling Cooler with active vibration cancellation; CCD temperature control is done with a Lake Shore Temperature Controller. A Varian Ion Pump and Activated Charcoal are used to maintain good vacuum and to prolong intervals between vacuum pump down. The various hardware components of the system are connected using distributed software architecture, and a web-based GUI allows remote and scripted operation of the instrument.
SpUpNIC (Spectrograph Upgrade: Newly Improved Cassegrain) is the extensively upgraded Cassegrain Spectrograph on the South African Astronomical Observatory's 74-inch (1.9-m) telescope. The inverse-Cassegrain collimator mirrors and woefully inefficient Maksutov-Cassegrain camera optics have been replaced, along with the CCD and SDSU controller. All moving mechanisms are now governed by a programmable logic controller, allowing remote configuration of the instrument via an intuitive new graphical user interface. The new collimator produces a larger beam to match the optically faster Folded-Schmidt camera design and nine surface-relief diffraction gratings offer various wavelength ranges and resolutions across the optical domain. The new camera optics (a fused silica Schmidt plate, a slotted fold flat and a spherically figured primary mirror, both Zerodur, and a fused silica field-flattener lens forming the cryostat window) reduce the camera’s central obscuration to increase the instrument throughput. The physically larger and more sensitive CCD extends the available wavelength range; weak arc lines are now detectable down to 325 nm and the red end extends beyond one micron. A rear-of-slit viewing camera has streamlined the observing process by enabling accurate target placement on the slit and facilitating telescope focus optimisation. An interactive quick-look data reduction tool further enhances the user-friendliness of SpUpNI
Until recently, software for instruments on the smaller telescopes at the South African Astronomical Observatory (SAAO) has not been designed for remote accessibility and frequently has not been developed using modern software best-practice. We describe a software architecture we have implemented for use with new and upgraded instruments at the SAAO. The architecture was designed to allow for multiple components and to be fast, reliable, remotely- operable, support different user interfaces, employ as much non-proprietary software as possible, and to take future-proofing into consideration. Individual component drivers exist as standalone processes, communicating over a network. A controller layer coordinates the various components, and allows a variety of user interfaces to be used. The Sutherland High-speed Optical Cameras (SHOC) instruments incorporate an Andor electron-multiplying CCD camera, a GPS unit for accurate timing and a pair of filter wheels. We have applied the new architecture to the SHOC instruments, with the camera driver developed using Andor's software development kit. We have used this to develop an innovative web-based user-interface to the instrument.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.