On Thu, 2 Jun 2005 22:39:21 -0700, Eunometic wrote
(in article . com):

I'm not sure I understand what you mean. There were 'rossete scans'
that ended up in latter versions of sidewinder thse use a sort of
rotating and oscialting mirror. These also ended up in early German
infrared seekers intended for terminal homing on the Wasserfall missile
but actually derived from infrared imaging systems such as "Spanner".

The slots or pattern may have formed the front end of a chopper amplifier,
which was the common way to work with infrared sources in the instrument
business at the time. Was there an internal reference IR source and detector
and a difference circuit? This might elliminate ECM and other common mode
noise.

-- Charlie Springer