LBT Q3 2007 Engineering LBT Q3 2007 Engineering ReviewReview

TAL Telescope Alignment.TAL Telescope Alignment.

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Highlights and Progress(Q3/2007)Highlights and Progress(Q3/2007) Completed new alignment plans for rigid secondary and LBC Procured alignment telescope accessories and mounting

brackets in preparation for Q4 alignment work. Assessed Laser Tracker technology; selected vendor, awaiting

budget decision. Determined that the blue hub is tilted to between 2 and 4 arc-

minutes from September engineering observations. Confirmed that earlier assumptions on plate scale sensitivity

to mirror separation were out by a factor of ~40 (in reality much 8 microns instead of 350+ microns).

Proposed new single-pass null-test for adaptive secondaries. Supporting Michael Andersen’s efforts in the AGW unit

specification document.

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Open IssuesOpen Issues LBC Blue alignment can be improved. Possible to check

hub alignment to GR axis using A-Scope. “Wall-eye” of PMs and other system flexures need to be

quantified and checked against available correction ranges of optical elements. Again, the A-Scope set-up for LBC alignment can give some useful measurements of that.

AGW support. FPIA sensitivity to focus and other low-order aberrations

uncertain. Quantitative investigation underway with Zemax-modelled CCD’s.

Awaiting budget decision on laser trackers, otherwise no large optics purchases anticipated for Q4-Q1.

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ProgressProgressQ2: Finalize LBC alignment procedure and improve image quality to the point that seeing limited images (on good nights) are achievable.

Alignment procedure finalized, alignment of LBC Red currently scheduled for November, possibly some Blue Hub alignment as well.

Q2: Q2: Procure alignment equipment Alignment telescope mounts and accessories

purchased. Purchase of Laser Tracker in Q1 ‘08 if approved.

Q2: Q2: Finalize and “publish” up-to-date Zemax models of various LBT modes

Work in progress, have working models of LBC Red, Blue and Gregorian modes.

Q2: Q2: Continue with investigation of tolerances and compare results to measured system performance

Work in progress.

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Q2: Work with software on collimation/pointing etc.

No outstanding software support issues, supporting MA for AGW work.

ProgressProgress

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PlanningPlanning Schedule

Alignment of LBC Red currently scheduled for November, possibly some Blue Hub alignment as well.

Purchase of Laser Tracker in Q1 ‘08 if approved. Alignment of rigid secondary in Q1 ‘08. Alignment of tertiary mirrors in Q4 ’07 (goal). Assistance of MA ongoing. FPIA investigation ongoing. Publish global coordinate system for LBT (one exists already). Publish various “final” Zemax models.

Resource Assistance from Software, Engineering groups as well as

various Germans, Italians and John Hill.