Josh Eisner and Peter Tuthill joined us last night. We intended to try out nonredundant aperture masking, but the skies did not cooperate. However, we made some progress on testing out the technique.
The approach masks off the telescope into discrete small apertures, and measures the visibility amplitude and phase for each pair of apertures. Peter has pioneered this approach on various telescopes, and Josh has been leading the effort here. We view this as an attractive "first light" mode for LBTI. It can work indpendently of the AO and will create images which utilize the full 22.6 m baseline of the interferometer.
The images below are those only an interferometrist could love. It shows the apertures inside LMIRCam and the power spectra (visibilities) that Peter derived from looking at an artificial source through these masks. They are exploring several mask designs, of which two are shown. The second image shows the PSF's he started from. The PSF had a significant defocus, which makes the single pinhole look like a binary. However, the power spectra appear to be measurable even for this case.
The next step is to get it working on the sky.
/groups/lbti/search/index.rss?tag=hotlist/groups/lbti/search/?tag=hotWhat’s HotHotListHot!?tag=hot1/groups/lbti/sidebar/HotListAdded tag - hotphinzPhil Hinz2010-10-15 20:37:53+00:002010-10-15 20:37:53addTag3phinzPhil Hinz2010-10-15 13:18:40+00:002010-10-15 13:18:40updated2First createdphinzPhil Hinz2010-10-15 13:05:39+00:002010-10-15 13:05:39created1weblog2010-10-15T13:18:40+00:00groups/lbti/weblog/b808eFalseFirst Night Results/groups/lbti/weblog/b808e/First_Night_Results.htmlPhil Hinz3 updatesFirst Night Results
It was an eventful first night on the LBT. Network connections failed, hardware refused to turn on, all the typical problems of a new instrument. Aft...Falsephinz2010-10-15T13:18:40+00:00hot/groups/lbti/search/index.rss?sort=modifiedDate&kind=all&sortDirection=reverse&excludePages=wiki/welcomelist/groups/lbti/search/?sort=modifiedDate&kind=all&sortDirection=reverse&excludePages=wiki/welcomeRecent ChangesRecentChangesListUpdates?sort=modifiedDate&kind=all&sortDirection=reverse&excludePages=wiki/welcome0/groups/lbti/sidebar/RecentChangesListmodifiedDateallRecent ChangesRecentChangesListUpdateswiki/welcomeNo recent changes.reverse5searchlist/groups/lbti/calendar/Upcoming EventsUpcomingEventsListEvents1Getting events…