NICMOS focus update as of August 6, 1998
The NICMOS focus data obtained on August 6, 1998, show that NIC3 focus
continues to drift away from its nominal setting. At FOM tilt = 0, it
would have a value which below its level at the end of SMOV in late May
last year.
Camera 2 focus remains basically unchanged, close to the nominal PAM
setting of 0.69 mm. During the focus monitoring visit on August 6,
camera 1 observed in parallel with camera 2, and its field of view
happened to have no star suitable for phase retrieval analysis.
The updated summary of the NICMOS focus history is given in the
Table and in the
focus history plot . Note
that, in the plot, focus during NIC3 campaigns is corrected for the
Secondary Mirror move while the Table contains the actual uncorrected
values.
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