Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.mrao.cam.ac.uk/projects/OAS/pmwiki/uploads/MROIDelayLineSW.RequirementsReview/INT-414-TSP-0004.pdf Äàòà èçìåíåíèÿ: Tue Apr 21 20:41:08 2009 Äàòà èíäåêñèðîâàíèÿ: Sat Mar 1 04:12:55 2014 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: ï ï ï ï ï ï ï ï ï ï ï ï ï ï

Commissioning Plan and Performance Verification Milestones for the MROI


INT414TSP0004 rev 0.5 Dated: November 7th 2007 Chris Haniff

Magdalena Ridge Observatory New Mexico Tech 801 Leroy Place Socorro, NM 87801,USA Phone: (505)835-6431 Fax: (505)835-6807 http://www.mro.nmt.edu


Revisions REV DATE AUTHOR Initial draft Included inputs from IDT Revised up to PVM4, PVM5 not updated Working on PVM4 and 5 Summary versions of all PVMs included COMMENTS

0.1 2007/7/19 CAH 0.2 2007/7/20 CAH 0.3 2007/8/03 CAH 0.4 2007/8/07 CAH 0.5 2007/11/07 CAH

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CONTENTS 1 2
2.1 2.2 2.3 2.4

PURPOSE ..................................................................................................................... 1 INTRODUCTION ...................................................................................................... 2
Background to the process ................................................................................................................ 2 The MROI approach.......................................................................................................................... 2 Structure of this document ................................................................................................................ 3 Acronyms used in this document ...................................................................................................... 3

3

PERFORMANCE VERIFICATION MILESTONES (PVMS) ............................. 5

3.1 PVM1 ­ First starlight on UT tip-tilt (TT) sensor ........................................................................... 7 3.1.1 Task definition ............................................................................................................................... 7 3.1.2 Items/tasks to be verified .............................................................................................................. 7 3.1.3 Subsystem requirements ............................................................................................................... 8 3.1.4 Proposed timescale and summary of required infrastructure................................................. 10 3.2 PVM2 ­ Closed loop operation of the TT system .......................................................................... 3.2.1 Task definition ............................................................................................................................. 3.2.2 Items/tasks to be verified ............................................................................................................ 3.2.3 Subsystem requirements ............................................................................................................. 3.2.4 Proposed timescale and summary of required infrastructure................................................. 3.3 PVM3 ­ First light in the BCA on the Fringe Tracker table ........................................................ 3.3.1 Task definition ............................................................................................................................. 3.3.2 Items/tasks to be verified ............................................................................................................ 3.3.3 Subsystem requirements ............................................................................................................. 3.3.4 Proposed timescale and summary of required infrastructure................................................. 3.4 PVM4 ­ First fringes at the FT combiner ...................................................................................... 3.4.1 Task definition ............................................................................................................................. 3.4.2 Items/tasks to be verified ............................................................................................................ 3.4.3 Subsystem requirements ............................................................................................................. 3.4.4 Proposed timescale and summary of required infrastructure................................................. 3.5 PVM5 ­ First closed-loop fringe tracking ...................................................................................... 3.5.1 Task definition ............................................................................................................................. 3.5.2 Items/tasks to be verified ............................................................................................................ 3.5.3 Subsystem requirements ............................................................................................................. 3.5.4 Proposed timescale ...................................................................................................................... 3.6 PVM6 ­ Closed-loop fringe tracking on long baselines ................................................................ 3.6.1 Task definition ............................................................................................................................. 3.6.2 Items/tasks to be verified ............................................................................................................ 3.6.3 Subsystem requirements ............................................................................................................. 3.6.4 Proposed timescale and summary of required infrastructure................................................. 3.7 PVM7 ­ Sensitivity at H=10 on long baselines with the Fringe Tracker ..................................... 3.7.1 Task definition ............................................................................................................................. 3.7.2 Items/tasks to be verified ............................................................................................................ 3.7.3 Subsystem requirements ............................................................................................................. 3.7.4 Proposed timescale and summary of required infrastructure................................................. 11 11 11 12 14 15 15 16 17 20 22 22 23 24 27 29 29 30 31 33 35 35 35 35 35 37 37 37 38 38

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3.8 PVM8 ­ First closure phase............................................................................................................. 3.8.1 Task definition ............................................................................................................................. 3.8.2 Items/tasks to be verified ............................................................................................................ 3.8.3 Subsystem requirements ............................................................................................................. 3.8.4 Proposed timescale and summary of required infrastructure................................................. 3.9 PVM9 ­ Sustained closure phase measurements on long-baseline triangles: ............................. 3.9.1 Task definition ............................................................................................................................. 3.9.2 Items/tasks to be verified ............................................................................................................ 3.9.3 Subsystem requirements ............................................................................................................. 3.9.4 Proposed timescale and summary of required infrastructure................................................. 3.10 PVM10 ­ Sensitivity at H=10 on long baselines with the science combiner ................................ 3.10.1 Task definition ........................................................................................................................ 3.10.2 Items/tasks to be verified........................................................................................................ 3.10.3 Subsystem requirements ........................................................................................................ 3.10.4 Proposed timescale and summary of required infrastructure ............................................ 3.11 PVM11 ­ First "rapid" relocation .................................................................................................. 3.11.1 Task definition ........................................................................................................................ 3.11.2 Items/tasks to be verified........................................................................................................ 3.11.3 Subsystem requirements ........................................................................................................ 3.11.4 Proposed timescale and summary of required infrastructure ............................................ 3.12 PVM12 ­ First "snapshot" image with 6 telescopes (H-10) .......................................................... 3.12.1 Task definition ........................................................................................................................ 3.12.2 Items/tasks to be verified........................................................................................................ 3.12.3 Subsystem requirements ........................................................................................................ 3.12.4 Proposed timescale and summary of required infrastructure ............................................ 3.13 PVM13 ­ First "snapshot" image with 6 telescopes (H=14) ......................................................... 3.13.1 Task definition ........................................................................................................................ 3.13.2 Items/tasks to be verified........................................................................................................ 3.13.3 Subsystem requirements ........................................................................................................ 3.13.4 Proposed timescale and summary of required infrastructure ............................................

39 39 39 40 40 42 42 42 44 44 46 46 46 47 48 49 49 49 51 51 53 53 53 54 54 57 57 57 58 58

27

SCHEDULE SUMMARY IN CONTEXT OF UT DELIVERIES ....................... 60

28 SUGGESTIONS FOR PROCESS FOR MOVING AHEAD WITH THIS DOCUMENT ..................................................................................................................... 61

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1

Purpose

The purpose of this document is to present an outline plan for the technical commissioning of the MRO Interferometer. For the purposes of this document, we have taken the definition of this task to mean: "Technical commissioning: the phase during which the technical and functional capabilities of the system are demonstrated in the final operational configuration under defined operating conditions. During commissioning, both verification and validation tests are performed on the complete system." This identifies technical commissioning of the interferometer as a separate exercise from subsystem testing, in which the different interferometer subsystems are tested individually. In this document it has been assumed that this subsystem testing has already been carried out successfully, and so here we are focusing on the testing of these systems as an integrated whole. The project must vigorously resist the temptation to use technical commissioning as the process by which individual subsystems are tested and debugged ­ this will simply not be possible in any efficient manner once multiple subsystem are integrated. This document has three main purposes: 1. It sets out the sequence of commissioning milestones, hereafter referred to as "Performance Verification Milestones" (or PVMs) for the technical commissioning. 2. It describes what each PVM seeks to achieve, and describes what specific verification tasks need to be performed to allow the project to announce that the milestone has been reached. 3. It describes what WBS elements need to be available for each PVM to be realized and for each interferometer subsystem, what level of capability is required at each of these events. It is likely that there will also be a separate activity at the MROI called "Scientific Commissioning". The detailed definition of this parallel activity ­ it is possible that elements of this activity might take place contemporaneously with the technical commissioning ­ and its specific function have yet to be specified. However, it is possible that its principal goal will be to provide an opportunity for the MROI teams to demonstrate to the scientific community the unique scientific capability of the interferometer prior to it becoming available for that community to use.

This "scientific commissioning" activity is unrelated to the formal verification process by which "the technical and functional capabilities of the system are demonstrated in the final operational configuration", and so does not fall within the scope of this document. 1


Readers should note that at this stage (revision 0.5), this is a working document. The final elaboration of the commissioning plan will involve a systemwide assessment of the complete set of PVM requirements and the resources that the project can make available at any given time by the PM. Readers should also note that in this version of the document (0.5), the descriptions and information regarding the first 5 PVMs is presented in much more detail than for the remaining 8 PVMs because at this stage it was felt that introducing too much detail of later PVMs might be premature. 2 Introduction

The current plan for commissioning the MROI involves the definition of a set of 13 Performance verification milestones (PVMs) each of which must be passed, sequentially, to validate the technical and functional performance of the array. 2.1 Background to the process

Historically, most interferometers have been deployed in an environment in which the drive to produce results ­ often in the face of competitor arrays ­ has meant that it has been difficult to allocate time to the careful and considered assessment, debugging and mending of noncompliant hardware and software. The upshot of this can have multiple undesirable consequences, for example: · · · The desired capability of the array may be delayed or never be realized. Downtime during scheduled observations can be high, leading to unhappy users and overstretched staff. Funding agencies can become wary of further support as the "promised" capability is never seen to emerge.

The early definition of a set of PVMs at the MROI is a deliberate strategy to help mitigate these types of problems. 2.2 The MROI approach

At the MROI the approach that has been proposed is to define a set of PVMs which provide a context within which the delivery of the interferometer and its subsystems can be delivered. The PVMs represent a set of highlevel goals, each associated with a key functional capability of the MROI, which allows the project management and stakeholders to assess the progress of the delivery of the interferometer and to verify that the "advertised" capabilities of the array are

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indeed being delivered. From an internal MROI project team perspective, the PVMs have a much more tangible and valuable role: · · · They will implicitly define the sequence of tasks and subsystems that need to be delivered as a function of time. They will explicitly define the capability of each of the interferometer subsystems needed as a function of time. They will specify the basis from which the Project Manager will be able to assess the resource implications ­ including staffing, hardware, and levels of expertise ­ for the overall delivery of the interferometer.

One important point to stress is that the PVMs identify the minimum capability that each subsystem must have realized by the time that the milestone is reached. It may very well be that it is logistically easier and more costeffective to deliver an enhanced capability earlier, than to "stretchout" the delivery schedule for any given subsystem to the maximum time permitted by the PVM schedule. The Project Manager will need to take this into account when utilizing the PVM to manage the activities of his staff, especially as the hidden costs of deferring activities and then reassembling a suitable team (often in the face of other deadlines) can easily be underestimated. 2.3 Structure of this document

In the following section (3), we present an outline of the 13 proposed PVMs for the MROI project. In each case, the PVM is described, the specific validation tests to be performed are outlined, and the implications on other subsystems are highlighted. In Section 4, a summary of the overall PVM timeline is presented. Finally, in Section 5 the System Architects provide some suggestion as to how they envisage this document will be used, and the next stages in developing a concrete implementation plan for the Technical Commissioning described herein. 2.4 Acronyms used in this document

ADC Atmospheric dispersion corrector BCA Beam combining area BCF Beam combining facility DL Delay line

DLA Delay line area

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ECS Enclosure control system FT Fringe tracking

FTT Fast tiptilt NAS Narrow angle sensor PVM Performance verification milestones TASS Telescope array supervisory software TCS Telescope control system UT Unit telescope

UTCS Unit telescope control software WAS Wide angle sensor WBS Work breakdown structure

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3

Performance verification milestones (PVMs)

The thirteen proposed PVMs can be summarized as follows. Singletelescope standalone milestones · · PVM1 ­ First starlight on UT tiptilt sensor: demonstrates telescope and wideangle sensor operation. PVM2 ­ Closed loop operation of the TT system: demonstrates TT system operation and supervisory control of TT loops to secondary mirror and UT mount.

Singletelescope milestones that require the BCA · PVM3 ­ First light in BCA on Fringe Tracker table: demonstrates beam relay, delay lines, beam compressors, vacuum system, switchyard and aspects of the alignment system to the inner BCF.

Twotelescope milestones · · PVM4 ­ First fringes at the FT combiner: demonstrates the delivery of light to the FT combiner, the FT combiner itself, and the FT detector system. PVM5 ­ First closedloop fringe tracking: demonstrates closing the FT/Delay line loop on a single baseline, stable fringe tracking and initial quicklook data analysis.

Threetelescope milestones · PVM6 ­ Closedloop fringe tracking on long baselines: demonstrates the bootstrapping capability of the array using a twoleg baseline. Verifies robustness to atmospheric fluctuations. PVM7 ­ Sensitivity at H=10 on long baselines (FT): confirms the sensitivity of the FT combiner under realistic observing conditions and with bootstrapping operational. PVM8 ­ First closure phase: confirms the delivery and operation of the science beam combiner. Verifies the parallel operation of two beam combiners and multibaseline fringe tracking. Tests initial data analysis capability for science combiner. PVM9 ­ Sustained closure phase measurements on longbaseline triangles: demonstrates robust bootstrapping with parallel combiners over

·

·

·

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long timescales. Verifies data analysis techniques for science combiner. · Multipletelescope milestones only worth performing when the number of telescopes is greater than 3 · PVM11 ­ First "rapid" relocation: verifies the ability to reconfigure the array and return to scientific operations reliably and efficiently. All major subsystems now operational in largely "automated" modes so as to support rapid return to operational capability when things are changed. PVM10 ­ Sensitivity at H=10 on long baselines (SCI): confirms the sensitivity of the Science beam combiner as advertised.

Sixtelescope milestones · PVM12 ­ First "snapshot" image with 6 telescopes (H10): demonstrates the delivery of the Phase A hardware and software, and demonstrates the system robustness for a ~46 hour tracking observation. At this stage the project is largely complete. PVM13 ­ First "snapshot" image with 6 telescopes (H=14): demonstrates the realization of the Phase A goals of the interferometer. Phase 1 ends.

·

The following subsections address each of these in more detail. In the first instance we outline the specific functionality to be verified, while in the second the requirements on other interferometric subsystems are identified.

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3.1 3.1.1

PVM1 ­ First starlight on UT tiptilt (TT) sensor Task definition

The principal goal of this PVM is to demonstrate that stellar light, in the form of the full 95mm diameter collimated beam, can be delivered, routinely, for acquisition to the narrowangle sensor on the UT optical table. Control of this PVM is to be local to a given telescope/enclosure combination. The proposed sequence of events is: 1. Open dome (possibly manually); 2. Command telescope to point to a given target; 3. Acquire target in wide angle sensor; 4. WAS subsystem finds target, communicates with TCS and centers target; 5. Acquire target on narrow angle sensor ­ display and log data; 6. Repeat items [2] thru [5] on a number of different targets. It should perhaps be made clear that PVM1 is not the same as the SATs for UT1. While some of the events are indeed components of the SATs for the first telescope delivered, the SATs include additional tasks for which a separate enumeration of Customerprovided "equipment" will need to be developed. Also, the SAT's will not cover all of the verification needed here. What equipment is needed to be delivered for the SAT of telescope 1 should be the focus of a separate document. 3.1.2 Items/tasks to be verified

For this PVM to be realized, it is suggested that at least the following activities need to have been demonstrated successfully: Obligatory components of this activity · That the UT can be mounted on one of its foundation interfaces. For reasons that will become evident at PVM3 and beyond, the central pad, or one on the western arm is preferable. That the UT can be integrated and operated successfully inside its enclosure. That all utilities can be provided to successfully operate a telescope inside its enclosure. That the control software associated with the telescope (TCS) and the narrowangle sensor can be coordinated using the Unit Telescope Control System (UTCS). That the wideanglesensor (WAS) subsystem can detect light, focus it, interrogate its images, and communicate appropriately with the TCS. 7

· · ·

·


· ·

That the narrowangle sensor (NAS) can detect light, focus it, and display this to a user sensibly. That appropriate local monitoring and logging of the activity of the enclosure, telescope, WAS and NAS systems takes place.

Optional (TBD) components of this activity · That the control software associated with the environmental monitoring system, the enclosure (ECS), the telescope (TCS), the narrowangle sensor and the wide angle sensor ­ i.e. all the subsystems that are being utilized during this PVM ­ can be coordinated using the Unit Telescope Control System (UTCS). That appropriate remote monitoring and logging of the activity of the enclosure, telescope, WAS and NAS systems takes place using a rudimentary version of the telemetry and engineering archives. That the sensing of the light on the NAS occurs at the same wavelengths that will be used during Phase 1 of the MROI deployment ­ this would imply delivery of the dichroic to be used in Phase 1.

·

·

3.1.3 Subsystem requirements

The requirements placed on the various subsystems of the interferometer by PVM1 are summarized in the table below:
WBS number 4.03.01 4.03.02 4.03.03 WBS name Unit telescope optics Unit telescope mounts Fast Tiptilt systems Required Notes Full functionality is required for 1 telescope. Full functionality is required for 1 telescope. Only at a level that includes minimal image analysis. Servoloop software/hardware is not required, only detector setup, image capture and display. No dichroic necessary. Full functionality is required. Full functionality is required apart from full connectivity of control software with the UTCS and environmental monitoring system.

4.03.04 4.03.05 4.04.00

ADCs Wide field acqn. systems Unit tel. enclosures

No

4.05.01 4.05.02 4.05.03

Beam relay system Vacuum system Beam compressors

No No No

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4.05.04 4.06.01 4.06.02 4.06.03 4.06.04 4.06.05 4.07.01 4.07.02 4.08.00 4.09.01 4.09.02 4.09.03 4.09.04 4.10.01 4.10.02 4..11.01 4.11.02 4.12.00 4.13.00 4.14.00 4.15.00

Turning mirrors Delay line (DL) system DL Trolleys DL pipes and supports DL metrology system DL software Fringe tracker NearIR science combiner Infrared arrays Software engineering Control infrastructure Supervisory system Data handling system Alignment system Wavefront sensors Data reduction tools Observation prep. tools BCF Unit tel. transporter Technical commissioning Environmental monitoring Scientific preparation Operations planning Research office building Workman lab R&ED demonstraton facility Lodging IT infrastructure

No No No No No No No No No Possibly No

Needed to write subsystem software. UTCS software to oversee WAS, NAS, TCS, and enclosure control system. Only needed in a rudimentary fashion. Only needed in a rudimentary fashion if non local archiving is verified. Needed at a level to align and focus the telescope. Only at a level that guarantees safety when opening an enclosure. Full software connectivity with the UTCS is not required. Needed for design activity. May be needed for prototyping/test. May be needed for prototyping/test. Needed for design activity.

No No No No

4.16.00 4.17.00 4.18.00 4.18.01 4.18.03 4.18.04 4.19.00

No No Possibly Possibly No



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3.1.4

Proposed timescale and summary of required infrastructure

Successful execution of PVM1 should occur as soon as the first unit telescope arrives on site and has been accepted. Summary of key required hardware at this time: · Telescope pads: all, because subsequent earthwork will disturb those already installed. In addition, existing pads will need time to settle before any telescopes are installed. Beam relay and vacuum can piers: all, because subsequent earthwork will disturb those already installed. In addition, existing piers will need time to settle before any hardware is installed. Monumentation: all, because subsequent earthwork will disturb those elements already installed. Enclosure: one, to enclose first UT. WAS system: one complete system. NAS system: one, but only the sensor and optomechanics. None of the control to close to FTT loop is needed. Software: only those aspects of the UTCS needed to coordinate telescope based activities are needed. Some limited data handling functionality. Environmental monitoring: only at a level that supports safe use of one telescope. Wavefront sensor: needed at the level of aligning and setting up one UT.

·

· · · · · · ·

Summary of key hardware items not needed at this time: · · · · · · · · · Beam relay system: any of the pipes and cans. Delayline system: any of the pipes or hardware & software. Beam compressors: any of this subsystem. Turning mirrors: any of this subsystem. Switchyards: any of this subsystem. Alignment system: any of this subsystem. Fringe tracking beam combiner: any of this subsystem. Science beam combiner: any of this subsystem. Offline software: none.

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3.2 3.2.1

PVM2 ­ Closed loop operation of the TT system Task definition

The principal goal of this PVM is to demonstrate that the FTT system can close the loop with the active secondary mirror such that a stellar image is stabilized sufficiently to meet the FTT performance requirements as the telescope tracks. In addition, the FTT system will need to demonstrate that it can send both fast control signals to the active secondary mirror and slow pointing updates to the telescope mount. Control of this PVM is to be local to a given telescope/enclosure combination. The proposed sequence of events is: 1. Open dome (possibly manually); 2. Command telescope to point to a given target; 3. Acquire target in wide angle sensor (if necessary); 4. WAS subsystem finds target, communicates with TCS and centers target (if necessary); 5. Acquire target on narrow angle sensor ­ display and log data; 6. NAS subsystem finds target, communicates with TCS such that target is centered; 7. FTT system closes loop with active secondary actuators and telescope mount ­ display and lo