Stray light comparison of off-axis and on-axis telescopes.

摘要

A comparison is made between two telescope types based on how well they suppress unwanted radiation. A single off-axis system is challenged by two on-axis designs possessing similar optical parameters. Each telescope is optimally designed in terms of stray light to establish a level playing field. Software modeling is used in the design and characterization of the systems. Key design features have been proven at the off-axis scatter facility at the Space Dynamics Laboratory of Utah State University. The candidate telescopes are judged on their response to an off-axis point source at the wavelengths of 0.6328 μm, 10.6 μm, and 25 μm, which takes into consideration the changing nature of surface scatter and diffraction effects. The off-axis and the on-axis reimaging systems were found to be of comparable quality, both being superior to the simple on-axis Cassegrain telescope.