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chara:glass_offsets

Recent glass offsets

We are in the process of determining default offsets for the new LDC glass. When using PAVO, please check here to see if a glass offset has already been measured for the baseline pair. If it has, type “goffset” into the ople server, select the correct telescope, and enter the glass offset.

If you are using a new baseline, please type “goffset” into ople server after toggling the glass and record the new glass offset for the moving cart and reference cart on this page (or send them to Gail). The goffset command will ask you to enter a goffset before exiting, just enter the same value.

  • E2 moving cart, W2 reference cart: goffset for E2 = -3.4, goffset for W2 = 0.

The dispersion will be high if the goffset is not set correctly. This could make it challenging to find fringes on fainter targets. If you have any trouble finding fringes, select a bright unresolved fringe finder that is expected to have strong fringes so that you can toggle the glass after fringes are found. This could be done using the IDL script pavo_ptsrc or JMMC SearchCal. Alternatively, select a star from the list of published CHARA diameters. For PAVO, go as bright as possible (V = 4th or 5th mag) and diameter < 0.4 mas for 300 m baseline, < 0.7 mas for 200 m baseline, and < 1.5 mas for 100 m baseline.

chara/glass_offsets.txt · Last modified: 2021/08/24 23:15 by gail_stargazer