The 5m Dome A Terahertz Explorer (DATE5) is a proposed terahertz telescope to be deployed in Dome A, Antarctica, to exploit one of the best observing conditions at terahertz wavelengths on earth. In this paper, a design configuration for the near-field holography of the DATE5 surface measurement is presented. Important factors, such as measurement distance, operating frequency, and signal source location, are discussed. Special efforts have been given to the reduction of truncation errors. Simulation results under typical signal-to-noise ratios and design parameters are also provided.

http://ap-s.ei.tuat.ac.jp/isapx/2013/pdf/121_2_0.pdf

Design study on near-field radio holography of the 5-meter Dome A Terahertz Explorer

The Atacama Large Millimeter/submillimeter Array (ALMA) is a joint project between astronomical organizations in
Europe, North America, and East Asia, in collaboration with the Republic of Chile. ALMA will consist of at least 54
twelve-meter antennas and 12 seven-meter antennas operating as an aperture synthesis array in the (sub)millimeter
wavelength range. It is the responsibility of ALMA AIV to deliver the fully assembled, integrated, and verified antennas
(array elements) to the telescope array.
After an initial phase of infrastructure setup AIV activities began when the first ALMA antenna and subsystems became
available in mid 2008. During the second semester of 2009 a project-wide effort was made to put in operation a first 3-
antenna interferometer at the Array Operations Site (AOS). In 2010 the AIV focus was the transition from event-driven
activities towards routine series production. Also, due to the ramp-up of operations activities, AIV underwent an
organizational change from an autonomous department into a project within a strong matrix management structure.
When the subsystem deliveries stabilized in early 2011, steady-state series processing could be achieved in an efficient
and reliable manner. The challenge today is to maintain this production pace until completion towards the end of 2013.
This paper describes the way ALMA AIV evolved successfully from the initial phase to the present steady-state of array
element series processing. It elaborates on the different project phases and their relationships, presents processing
statistics, illustrates the lessons learned and relevant best practices, and concludes with an outlook of the path towards
completion.

/pdf/assembly-integration-and-verification-aiv-in-alma-series-2sklehah5z.pdf

Assembly, integration, and verification (AIV) in ALMA: series processing of array elements

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

https://www.eso.org/sci/libraries/SPIE2012/8449-6.pdf

System engineering of the Atacama Large Millimeter/submillimeter Array

The Atacama Large Millimeter/submillimeter Array (ALMA) Band 10 receiver covering 787 to 950 GHz is the highest frequency receiver of the ten bands envisioned for the ALMA Front End system. The Band 10 receivers have been undergoing installation and commissioning since 2012. After the Band 10 receiver tuning scripts (Josephson currents suppression, LO power optimization) and operation procedures had been developed and implemented, astronomical verification procedures (radio pointing, focus, beam squint, and end-to-end spectroscopic verification) were established in single dish mode at the ALMA Operations Support Facility (OSF; 2900 m elevation). Subsequently, the first Band 10 astronomical fringes were achieved at the Array Operations Site in October 2013 (AOS; 5000 m elevation). This is the highest frequency ever achieved by a radio interferometer and opens up a new window into submillimeter astrophysics.

ALMA band 10 (787-950 GHz) first astronomical fringes

The Atacama Large Millimeter/submillimeter Array (ALMA) is a joint project between astronomical organizations in
Europe, North America, and East Asia, in collaboration with the Republic of Chile. ALMA consists of 54 twelve-meter
antennas and 12 seven-meter antennas operating as an aperture synthesis array in the (sub)millimeter wavelength range.
Assembly, Integration, and Verification (AIV) of the antennas was completed at the end of the year 2013, while the final
optimization and complete expansion to validate all planned observing modes will continue. This paper compares the
actually obtained results of the period 2008-2013 with the baselines that had been laid out in the early project-planning
phase (2005-2007).
First plans made for ALMA AIV had already established a two-phased project life-cycle: phase 1 for setting up
necessary infrastructure and common facilities, and taking the first three antennas to the start of commissioning; and
phase 2 focused on the steady state processing of the remaining units. Throughout the execution of the project this lifecycle
was refined and two additional phases were added, namely a transition phase between phases 1 and 2, and a closing
phase to address the project ramp-down. A sub-project called Accelerated Commissioning and Science Verification (ACSV)
was carried out during the year 2009 in order to provide focus to the whole ALMA organization, and to
accomplish the start-of-commissioning milestone. Early phases of CSV focused on validating the basic performance and
calibration. Over time additional observing modes have been validated as capabilities expanded both in hardware and
software.
This retrospective analysis describes the originally presented project staffing plans and schedules, the underlying
assumptions, identified risks and operational models, among others. For comparison actual data on staffing levels, the
resultant schedule, additional risks identified and those that actually materialized, are presented. The observed
similarities and differences are then analyzed and explained, and corresponding lessons learned are presented.

The ALMA assembly, integration, and verification project: a retrospective analysis

The Atacama Large Millimeter/submillimeter Array (ALMA) will consist of at least 54 twelve-meter antennas and 12
seven-meter antennas operating as an aperture synthesis array in the (sub)millimeter wavelength range. The ALMA
System Integration Science Team (SIST) is a group of scientists and data analysts whose primary task is to verify and
characterize the astronomical performance of array elements as single dish and interferometric systems. The full set of
tasks is required for the initial construction phase verification of every array element, and these can be divided roughly
into fundamental antenna performance tests (verification of antenna surface accuracy, basic tracking, switching, and on-the-fly rastering) and astronomical radio verification tasks (radio pointing, focus, basic interferometry, and end-to-end
spectroscopic verification). These activities occur both at the Operations Support Facility (just below 3000 m elevation)
and at the Array Operations Site at 5000 m.

ALMA array element astronomical verification

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ALMA array element astronomical verification