Hunt for Molecules, Paris, 2005-Sep-20

Software Software Development for Development for ALMAALMA

Robert LUCASRobert LUCASIRAM IRAM Grenoble FranceGrenoble France

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Science Requirements

• Science Software Requirements Committee work– Started in 1999, relatively early in the project– About 15 scientists from Europe, US, Japan– General requirements ready in 2002– More detailed requirements by subsystem– Now one scientist attached to each subsystem to

follow up the development work, answer questions, participate in testing.

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Main Goals

• Motivated by Science Requirements• Deal with a large variety of projects

– Observing should be relatively easy at mm wavelengths, site is good

– Much more difficult in sub-mm range

• High degree of automation needed to guarantee observing efficiency at high data rate

• Deliver data of controlled quality• Use should be easy for the non-specialist

(unique instrument).

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Proposal/Project Preparation

• Uses an Observing Tool to prepare proposal submission and actual project editing

• This tools knows the standard observer modes• Has novice and expert modes• Translates astronomical information into observing

parameters• Provides reasonable defaults• Has components for observation setup, spectral setup,

sensitivity calculation, …• It prepares the scheduling blocks, and informs the user of

specific resources needed (data rate, data processing).

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Scheduling

• Dynamic, flexible scheduling is an essential feature to allow optimized use of variable site conditions

• Use both stringency and scientific rating stringency = ratio of total available time to time during

which a given programme could be scheduled

• Project split in scheduling blocks– They cannot be split– They may be logically linked for complex projects

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Observations

• Control command language– simple, easily editable, programmable– control all basic hardware components– provides a way to develop the basic Observer

modes and the Observatory modes

• Operator interface– Used to control the actual operation of hardware

and of the software subsystems.

• Staff Astronomer Interface– Used to perform quality control

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Data Acquisition and Archiving

• A Science Data Model has been developed to handle the science data and associated observing parameters, and auxiliary data

• Should be well suited for archiving and archival use of science data

• Data written in real time into this model.• Mainly developed here at Paris Observatory.

(f. Viallefond, M. Caillat, …)

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On-Line Calibration

• Needed in quasi-real time to ensure required data quality:– pointing, focus, delay measurements, …– Perform atmosphere calibration using state-of-the-art

atmosphere model, optimize use of radiometric phase correction

– Monitor atmosphere phase quality on phase calibrators and amplitude calibrators

– Feedback to observing process and to dynamic scheduling• Developped at IRAM (Grenoble)

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Quick Look

• Display observing parameters and monitor on-line calibration

• Provide feedback to operators and staff astronomers on the site on the quality of observations, of calibration, of data

• Visual check of the data acquired itself (e.g. display spectra, raw image)

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Science Pipeline

• Run at the end of the observing• Perform data reduction in a quasi-automated

way for most projects• An essential input for quality control by staff

astronomers• Will need to be tested by the staff during the

first years of science operation• Seen as an essential element to make ALMA

well open to a wide community

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Off-Line Data Reduction

• Based on AIPS++ which is now essentially focused on ALMA and EVLA.

• Development is regularly tested by would-be users and benchmarked against data processing requirements.

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Development Process

• Use of ALMA Common Software (ACS)– ‘Middle-ware’ layer that hides the underlying hardware /

operating system– Ensures distributed software deployment: (CORBA based, for

the specialists)

• Common rules of software engineering• Regular releases (6-month); but frequent integrations

(1-month)• Enforced testing policy

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Organisation

• Computing IPT led by B. Glendenning, G. Raffi, K. Tatematsu

• Subsystems:– Software subsystems: Prop. Prep.(UK), Scheduling(NRAO),

Control(NRAO), Correlator(NRAO), Telescope Calibration(IRAM), Pipeline(NRAO), Off-Line(NRAO), Archive(ESO), Executive(ESO), ACS(ESO), Operations(ESO), ACA(Japan)

– Other: SSR (IRAM), High Level Arch.(ESO), Software Eng.(ESO), Int. and Testing(ESO)

• Many phone meetings and travel required …

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Development Status

• In parallel: support for antenna evaluation, laboratory integration with prototype system (control/correlator)

• Design, prototyping of the final end-to-end system• Integration of the whole system very early (R1,R2) but with

limited functionality• Release R3 for 2005 Oct 01, emphasis of simulation of hardware• Support ATF (VLA test site) operation early during 2006.• On-site commissioning and science verification in 2007/2008