Atacama Large Millimeter/

submillimeter Array - ALMA

ASAC Charge 3For Oct 31 ASAC Report to ALMA Board

Al WoottenJAO Interim Project Scientist

Charges from ALMA Board recvd 2007 July 26

3. Review the calibration plan and scientific aspects of Assembly, Integration, Verification testing and for Commissioning. Being mindful of the finite resources (human, financial) available, are changes necessary or desirable for scientific reasons to the plans being implemented?

Calibration Plan reviewed by ASAC 2006 September.

Presentation by Mangum

Charge 3, continued AIV testing overview follows Commissioning and Science Verification Plan

reviewed by ASAC September 2006. Further developed at f2f meeting 2006 Oct at ESO. PS Hills, DPS Peck currently asessing plan. Two Commissioning Scientist positions currently

advertised to join the Santiago team. Presentation by Wootten, Peck.

System Integration and Verification: DefinitionSame process as is required of the

subsystem builders, but at a larger level:1. Integration of the subsystems into a

minimal system,2. Design verification of the system

(against the set of system requirements), System Verification Plan System Verification Matrix System Compliance Matrix

3. Acceptance tests of initial and subsequent integrated subsystems.

Where does Integration and Verification happen? The tasks are distributed between P-SI

and Chilean AIV, Original concept was that a nearly complete

system of final design would be verified at P-SI. P-SI is now understood to be limited by

schedule, other demands, and available hardware (discussed in next talk) and will accomplish as much verification as possible within the time/priorities available,

Anticipate that P-SI will show stable interferometric performance with a subset of the final design, and perhaps some amount of formal system verification.

Remainder of verification, using the final production design of equipment, falls onto Chilean AIV and Science Commissioning.

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OSF Interferometry

OSF Facility

Antenna 2 – Dec 07

BE 4FE 2

Ant 1 A,I V

Ant 2 A,I V

V

Interim Lab

Move to AOS

AIPC and ACC

Antenna Inspection Point Chile (AIPC) is a meeting milestone, same as Test Readiness Review for acceptance testing.

Hardware and vendor software are final, Test procedures and instruments are

ready and agreed, ALMA’s contribution to acceptance testing

is / will be ready. Acceptance (ACC) is a milestone

marking the acceptance of the antenna at the conclusion of successful acceptance testing (and other criteria), and the start of ALMA’s antenna integration

Vertex AIPC and ACC

Vendor Testing

MC Software

Lab Holog Tx

Environmental

Front End

OPT(rest of ALMA antenna subsystems)

Joint Tstng ALMA IntegrationVendor Integration

OSF Facilities

Holog Rx

RFI Testing

Back End A/D, Wraps

Mockup Racks

Cables, Pipes, Cryo

Current Work

For Vertex A#1 delivery: Develop detailed schedule for the

acceptance tests (AIPT-NA), Develop detailed plan for deliveries by

ALMA to AT process (AIV), Initiate meetings to coordinate

players in these deliveries. Repeat same steps for 12-m TP

antennas.

Definitions

Assembly, Integration and Verification (AIV) is a construction activity led by the JAO Project Engineer to integrate the ALMA sub-systems into a single working system.

Commissioning (C) covers initial testing, interaction with AIV and other construction IPTs to identify and resolve faults, optimization, training of Operations staff and documentation

Science Verification (SV) is the end-to-end testing of an ALMA science mode done using a science project proposed by a user, who may be external (ASAC).

An ALMA public image (API) is a large-scale project whose primary purpose is to convince the wider community/public of the value of ALMA (ASAC).

CSV = Commissioning and Science Verification

Equipment available

CSV starts with the delivery of a verified 3-element interferometer at the AOS, although there are pre-commissioning activities at the ATF and in support of AIV.

Bands 3, 4, 6, 7, 8, 9 available (maybe not 4 and 8 on the first few antennas)

All types of 12m antenna used for interferometric commissioning.

Test single-dish and interferometric observing in parallel; 2 subarrays.

Initial configurations compact; thereafter First Science Configurations as already defined

Baseline correlator + Tunable Filter Bank

Early Science – current definition

At least 16 antennas fully commissioned (more in process of integration)

Receiver bands 3, 4, 6, 7, 8, 9 Interferometry in single field or pointed

mosaic mode Significant range of spectral modes,

including TFB (initial priorities identified) Circular and linear polarization (not mosaic) Single-dish mosaic (position and beam-

switch) and OTF. 2 subarrays operational

Timescales

CSV milestone on handover of verified 3-element interferometer at AOS (currently 2009Q1)

Early Science decision point (which modes to be offered) CSV + 12 months

Early Science CSV + 20 months (For reference, 16 antennas available

for commissioning CSV + 15 months)

AIV Activities

AIV is responsible for: Antenna acceptance Antenna integration Single-antenna tests at OSF Single-baseline interferometry at OSF Single-antenna and single-baseline interferometry

at AOS CSV team needs to be closely involved in

these tests, both to contribute experience and to train new staff.

This is an important issue because of schedule overlap between initial antenna acceptance and ATF tests.

Main CSV activities (1)

Close-packed array antennas 1-4 on closely-spaced pads Band 3 only

Early Science array Additional bands Baselines to 4(?)km – depends on pad availability Correlator configurations Mosaics Polarization Addition of total power data Verification against Science Requirements

Main CSV activities (2)

Observation calibrations Phase calibration, fast switching and WVR

development Calibrator surveys (i.e. how to find them

efficiently) Temperature and flux scale Bandpass Instrumental polarization

Antenna and array calibrations Pointing, focus Primary beam and surface Antenna location Delay

Main CSV activities (3)

Single-dish modes Mosaic with beam and position switching On-the-fly mapping Autocorrelation and continuum total

power [Frequency switching] Total power calibration

ACA 7m array (from CSV + 12 months, roughly)

Task durations (1)

Split into broad categories: Commission observing modes Observation calibration Array and antenna calibration Single-dish ACA 7m array

Estimate durations and approximate phasing within CSV phase up to early Science

Many activities in parallel (flexibility; weather) Assumptions about SV fraction, array

downtime

Task durations (2)

Current numbers: Modes 230 days Observation calibration 150 days Array/antenna calibration 95 days Single dish 60 days (in parallel) ACA 7m array in parallel

Assume 20% downtime from outside factors Additional downtime from failures during CSV tests

are included in the task durations (expect 40-50% downtime in total from experience at other telescopes)

<10% SV fraction Consistent with a ~20-month programme Use ATF experience to define, document and assess time

needed for CSV procedures

Staffing required (CSV to CSV+20)

Description Number

Shifts Total (incl.turno)

Duty scientist 1 2 5

Observing calibration

2 1 5

Antenna and array calibration

2 1 5

Single-dish 1 1 2

Modes, imaging, docs, SV

3 1 7

Management 4 1 4

ACA 7m array

3 1 7 (from CSV+12)

Total 28 (to CSV+12)35 (from CSV+12)

Staffing available

Project Scientist + Deputy + 3 commissioning scientists

Science IPT staff on rotation Division of Science Operations Ad hoc specialists ARC staff on rotation

Concept is that Operations staff form an integral part of the commissioning team: there is no “handover”

Key working relationships between PS, HSO and PE.

Staffing profile

Required/available2008 20/31.52009 28/332010 35/35.5Numbers 2011-2012 TBD, but essentially

no Science IPT manpower available to supplement Operations.

Marginal, given the additional duties of Operations staff: more tuning required.

Efficiency factor issues (standard turno assumed)

Science Verification

Main goals Test ALMA modes end-to-end (includes projects

from user community) Feedback to CSV team Early access to ALMA data for the community

Modes fully commissioned before SV; PS responsible for decision to issue call

Open call for proposals, fast, not using formal machinery; review for scientific value (+external) and feasibility (CSV team)

Data public immediately Projects executed by CSV team/Operations;

include QA ALMA Public Images are a subset of SV

Verification

Draft verification matrix available Need to demonstrate that ALMA

meets its science requirements, but with an incomplete array.

Verification matrix is more complex, parameterized by number of antennas, range of baselines, …..

Scaling for sensitivity is straightforward, image fidelity and dynamic range somewhat less so.

Commissioning after Early Science

Much still to do, including completion of ACA 7m array, Band 10, more antennas, …

Primarily carried out by Operations staff

Planning just starting …

Issues (1)

Role of proto-CSV team in antenna acceptance, interface with AIV test scientists

Potential conflict between ATF tests and antenna acceptance – availability of trained people

Staffing and availability of key skills (improving, but still crucial).

JAO (PS and deputy in post) Science IPT (now advertising additional

executive posts associated with commissioning)

Commissioning scientists Operations AIV test scientists

Issues (2) Parallel commissioning of 12m array and

ACA When do ACA 12m antennas move to ACA

site? Requirement to commission ACA correlator

early Manpower required if commissioning is

concurrent Staff availability from DSO inevitably

decreases in the run-up to Early Science Percentage availability for different

types of position (research fraction; other commitments; …..)

Commissioning is always squeezed between the completion of construction and the start of science operations.

www.alma.info

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership among Europe, Japan and North America, in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere, in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in Taiwan and in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC). ALMA construction and operations are led on behalf of Europe by ESO, on behalf of Japan by the National Astronomical Observatory of Japan (NAOJ) and on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI).

www.alma.info

The Atacama Large Millimeter Array (ALMA) is an international astronomy facility. ALMA is a partnership between Europe, North America and Japan, in cooperation with the Republic of Chile. ALMA is funded in the darkest woods but she got tired. Lo and behold, there in front of her was a wee cabin. Going inside - bold child that she was, after years of an excessively generous upbringing - she found three bowls of porridge. She suddenly realized how hungry she was - my, it must have been a whole day since she had eaten properly. Tasting the first bowl, she found it tooooo hot. The second bowl was tooooo cold. She found the third bowl was just right, and which is managed by Associated Universities, Inc. (AUI), on behalf of Europe by ESO, and on behalf of Japan by the National Astronomical Observatory of Japan.