1 / 6

LBT Q4 2007 Engineering Review

TAL Telescope Alignment. LBT Q4 2007 Engineering Review. Highlights and Progress(Q4/2007). See INSP for LBC alignment activities Verified procedure for aligning alignment telescope to Gregorian rotator axes. Measured M3 rotator hub to be decentred by ~ 8 mm and tilted by ~ 15’.

myra
Download Presentation

LBT Q4 2007 Engineering Review

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. TAL Telescope Alignment. LBT Q4 2007 Engineering Review

  2. Highlights and Progress(Q4/2007) See INSP for LBC alignment activities Verified procedure for aligning alignment telescope to Gregorian rotator axes. Measured M3 rotator hub to be decentred by ~ 8 mm and tilted by ~ 15’. Formulated mathematics to calculate asymmetrical aberration for any combination of decentre and tip/tilt of m2, this is eventually going into active optics control, using output from AGW to more accurately determine position of M2. Useful publishable discovery: when coma is tipped out on-axis, one of the two nodes of binodal astigmatism is also zero for this field point. Determined that A-scope is in need of calibration at around the 2’ level.

  3. Open Issues See INSP for LBC related alignment issues. “Wall-eye” of PMs and other system flexures need to be quantified and checked against available correction ranges of optical elements. Some good results so far for LBC, we seem to be capable of achieving co-pointing with adjustments within active optics range, need to determine similar data for Gregorian modes. AGW and Active Optics. A lot of theoretical work still needed to optimize the alignment given data from AGW. Adjusting one of astigmatism, coma, focal plane flatness and pointing while maintaining the other three requires a lot of detailed analysis. FPIA shown to be very quirky. Jury still out on efficacy of recent “improvements”. Awaiting budget decision on laser trackers, otherwise no large optics purchases anticipated for Q4-Q1.

  4. Progress Q3: LBC Blue alignment can be improved. Possible to check hub alignment to GR axis using A-Scope. • Done, 0.5” images achieved with improved alignment beyond that needing verification. Q3: “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. • LBC results acceptable, more data needed for Gregorian modes. Q3: AGW support. • Ongoing, this becomes part of overall responsibility for active optics. Q3: FPIA sensitivity to focus and other low-order aberrations uncertain. Quantitative investigation underway with Zemax-modelled CCD’s • Problems identified, possibly solved by implemented changes, jury still out.

  5. Progress Q3: Awaiting budget decision on laser trackers, otherwise no large optics purchases anticipated for Q4-Q1. • No Change in 3 months.

  6. Planning • Schedule • Dry run installation of M2 hub in second week of January ‘08. • Purchase of Laser Tracker in Q1 ‘08 if approved. • Alignment of rigid secondary in Q1 ‘08. • Alignment of tertiary mirrors in Q1 ’08. • FPIA investigation ongoing. • Continue work on active optics. • Resource • Assistance from Software, Engineering groups as well as various Germans, Italians and John Hill.

More Related