From: "Vladimir Galogaza" 
To: "ATM shore" 
Reply-To: "Vladimir Galogaza" 


>I am wondering if the quality required in a diagonal depends on the
>distance from the diagonal to the focal plane.   If the diagonal is very
>close to the focal plane, perhaps error in the diagonal surface can't do
>much damage....
 >. . . Richard

Reading this and subsequent discussion I wander if, taking into account
statistical nature of surface error  numbers ( Strehl, RMS, PV) these are
linearly additive for two or more subsequent mirrors or some other
relationship has to be used to determine  final   error resulting from
individual errors.
( James?)

Vladimir.

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