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Apertures

The objective here is to direct the light from an object of interest to a particular point (an aperture) in the focal plane. Apertures are specified in angular units. They cause the tangent-plane coordinates ξ,η to be modified to ξ'η', as follows:

ξ' = ξ+ (-xA sinψ- yA cosψ)

η' = η+ (+xA cosψ- yA sinψ)

where xA,yA is the aperture position as given to the TCS.



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Mon Mar 1 17:52:09 GMT 1999