title: Fast computation of the narcissus reflection coefficient for the Herschel far-infrared/submillimeter-wave Cassegrain telescope.
abstract: Placement of a scatter cone at the center of the secondary of a Cassegrain telescope greatly reduces Nareissus reflection. To calculate the remaining Narcissus reflection, a time-consuming physical optics code/such as GRASP8 is often used to model the effects of reflection and diffraction. Fortunately, the Cassegrain geometry is sufficiently simple that a combination of theoretical analysis and Fourier propagation can yield rapid, accurate results at submillimeter wavelengths. We compare these results with those from GRASP8 for the heterodyne instrument for the far-infrared on the Herschel Space Observatory and confirm the effectiveness of the chosen scatter cone design.
authors.affiliation: U.S. Naval Research Laboratory, 4555 Overlook Avenue, Washington, DC 20375-5320, USA. lucke@nrl.navy.mil
authors.forename: Robert L
authors.initials: RL
authors.lastname: Lucke
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Fischer
authors.forename: Arturo M
authors.initials: AM
authors.lastname: Polegre
authors.forename: Douwe A
authors.initials: DA
authors.lastname: Beintema