ALMA operation support software and infrastructure

The Atacama Large Millimeter/submillimeter Array (ALMA) will be composed of 66 high precision antennae located at 5000 meters altitude in northern Chile. This paper will present the methodology, tools and processes adopted to system engineer a project of high technical complexity, by system engineering teams that are remotely located and from different cultures, and in accordance with a demanding schedule and within tight financial constraints. The technical and organizational complexity of ALMA requires a disciplined approach to the definition, implementation and verification of the ALMA requirements. During the development phase, System Engineering chairs all technical reviews and facilitates the resolution of technical conflicts. We have developed analysis tools to analyze the system performance, incorporating key parameters that contribute to the ultimate performance, and are modeled using best estimates and/or measured values obtained during test campaigns. Strict tracking and control of the technical budgets ensures that the different parts of the system can operate together as a whole within ALMA boundary conditions. System Engineering is responsible for acceptances of the thousands of hardware items delivered to Chile, and also supports the software acceptance process. In addition, System Engineering leads the troubleshooting efforts during testing phases of the construction project. Finally, the team is conducting System level verification and diagnostics activities to assess the overall performance of the observatory. This paper will also share lessons learned from these system engineering and verification approaches.

2020

After eight observing Cycles, the Atacama Large Millimeter-submillimeter Array (ALMA) is capable of observing in eight different bands (covering a frequency range from 84 to 950 GHz), with 66 antennas and two correlators. For the current Cycle (7), ALMA offers up to 4300 hours for the 12-m array, and 3000 hours on both the 7-m of the Atacama Compact Array (ACA) and TP Array plus 750 hours in a supplemental call. From the customer perspective (i.e., the astronomical community), ALMA is an integrated product service provider, i.e. it observes in service mode, processes and delivers the data obtained. The Data Management Group (DMG) is in charge of the processing, reviewing, and delivery of the ALMA data and consists of approximately 60 experts in data reduction, from the ALMA Regional Centers (ARCs) and the Joint ALMA Observatory (JAO), distributed in fourteen countries. Prior to their delivery, the ALMA data products go through a thorough quality assurance (QA) process, so that the a...

2002

The Atacama Large Millimeter Array (ALMA) is a joint project involving astronomical organizations in Europe, North America and Japan. ALMA will consist of 64 12-m antennas operating in the millimetre and sub-millimetre wavelength range, with baselines of more than 10 km. It will be located at an altitude above 5000 m in the Chilean Atacama desert. The ALMA Computing group

The Atacama Large Millimeter Array (ALMA) is a project to build a radio interferometric telescope containing a large number of antennas (nominally 64) at a high site in Chile operating in the mm and sub-mm spectral region. With the addition of a Japan in the last year, ALMA is now a global partnership with participation by institutes in Asia, Europe, and North America. The scope of the ALMA Software includes all aspects: observing script creation through GUIs, dynamic scheduling depending on weather and instrumental parameters, instrument control (including the correlator device, capable of producing data at more than 1 GB/s), data handling and formatting, data archiving and retrieval, and automatic and manual data processing systems. The scope has recently been increased to support telescope operations (e.g., referee support). This ambitious scope is being implemented by a very distributed team, with approximately 60 members at institutes in 10 countries. This paper will describe s...

Journal of Infrared, Millimeter, and Terahertz Waves, 2010

The Atacama Large Millimeter/submillimeter (ALMA) Array Front End (FE) system is the first element in a complex chain of signal receiving, conversion, processing and recording. 70 Front Ends will be required for the project. The Front End is designed to receive signals in ten different frequency bands. In the initial phase of operations, the antennas will be fully equipped with six bands. These are Band 3 (84-116 GHz), Band 4 (125-163 GHz), Band 6 (211-275 GHz), Band 7 (275-373 GHz), Band 8 (385-500 GHz) and Band 9 (602-720 GHz). It is planned to equip the antennas with the missing bands at a later stage of ALMA operations, with a few Band 5 (163-211 GHz) and Band 10 (787-950 GHz) receivers in use before the end of the construction project. The ALMA Front End is far superior to any existing receiver systems; spin-offs of the ALMA prototypes are leading to improved sensitivities in existing millimeter and submillimeter observatories. The Front End units are comprised of numerous elements, produced at different locations in Europe, North America and East Asia and are integrated at several Front End integration centers (FEIC) to insure timely delivery of all the units to Chile. The North American FEIC (NA FEIC) is at the National Radio Astronomy Observatory facility in Charlottesville, Virginia, USA. This paper describes the design and performance of the test set used at the NA FEIC to check the performance of the Front Ends, following integration and prior to shipment to Chile.

Observatory Operations: Strategies, Processes, and Systems V, 2014

The Atacama Large Millimeter /submillimeter Array (ALMA) will be a unique research instrument composed of at least 66 reconfigurable high-precision antennas, located at the Chajnantor plain in the Chilean Andes at an elevation of 5000 m. The observatory has another office located in Santiago of Chile, 1600 km from the Chajnantor plain. In the Atacama desert, the wonderful observing conditions imply precarious living conditions and extremely high operation costs: i.e: flight tickets, hospitality, infrastructure, water, electricity, etc. It is clear that a purely remote operational model is impossible, but we believe that a mixture of remote and local operation scheme would be beneficial to the observatory, not only in reducing the cost but also in increasing the observatory overall efficiency. This paper describes the challenges and experience gained in such experimental proof of the concept. The experiment was performed over the existing 100 Mbps bandwidth, which connects both sites through a third party telecommunication infrastructure. During the experiment, all of the existent capacities of the observing software were validated successfully, although room for improvement was clearly detected. Network virtualization, MPLS configuration, L2TPv3 tunneling, NFS adjustment, operational workstations design are part of the experiment.

2002

The Atacama Large Millimeter Array (ALMA)[1] is a joint project between astronomical organizations in Europe and North America. ALMA will consist of at least 64 12-meter antennas operating in the millimeter and sub-millimeter range, with baselines up to 14 km. It will be located at an altitude above 5000m in the Chilean Atacama desert.

Astrophysics and Space Science, 2007

The Atacama Large Millimeter/submillimeter Array (ALMA) is an international radio telescope under construction in the Atacama Desert of northern Chile. ALMA will be situated on a high-altitude site at 5000 m elevation which provides excellent atmospheric transmission over the instrument wavelength range of 0.3 to 3 mm. ALMA will be comprised of two key observing components-an array of up to sixty-four 12-m diameter antennas arranged in a multiple configurations ranging in size from 0.15 to ~14 km, and a set of four 12-m and twelve 7-m antennas operating in closelypacked configurations ~50m in diameter (known as the Atacama Compact Array, or ACA), providing both interferometric and total-power astronomical information. High-sensitivity dual-polarization 8 GHz-bandwidth spectralline and continuum measurements between all antennas will be available from two flexible digital correlators. At the shortest planned wavelength and largest configuration, the angular resolution of ALMA will be 0.005". The instrument will use superconducting (SIS) mixers to provide the lowest possible receiver noise contribution, and specialpurpose water vapor radiometers to assist in calibration of atmospheric phase distortions. A complex optical fiber network will transmit the digitized astronomical signals from the antennas to the correlators in the Array Operations Site Technical Building, and post-correlation to the lower-altitude Operations Support Facility (OSF) data archive. Array control, and initial construction and maintenance of the instrument, will also take place at the OSF. ALMA Regional Centers in the US, Europe and Japan will provide the scientific portals for the use of ALMA; a call for early science observations is expected in 2009. In this paper, we present the status of the ALMA project as of mid 2006.

2003

The Atacama Large Millimeter Array (ALMA) is a joint project involving astronomical organizations in Europe and North America. The primary challenge to the development of the software is the fact that its development team is extremely distributed geographically. In addition it has very ambitious goals covering the whole end-to-end software system. The software development approach, based also on the experience of previous large projects is very pragmatic and contains elements of various methodologies, from the classical top-down model, to early prototyping, incremental development, and even aspects inspired to agile methodologies. INTRODUCTION The Atacama Large Millimeter Array (ALMA) is a joint project involving astronomical organizations in Europe and North America. ALMA will consist of at least 64 12meter antennas operating in the millimeter and submillimeter range. It will be located at an altitude of about 5000 m in the Chilean Atacama desert (see Ref. [1]). Fig.1 shows the ALM...

2001

The Atacama Large Millimeter Array (ALMA) is a joint project between astronomical organizations in Europe, USA and Japan. ALMA will consist of at least 64 12-meter antennas operating in the millimeter and sub-millimeter wavelength range, with baselines up to 10 km. It will be located at an altitude above 5000m in the Chilean Atacama desert [1].