Optical Performance Data for the UK Infrared Telescope; Atmospheric Seeing Effects in the Infrared

摘要

Aperture diffraction modulation transfer functions (MTF) were calculated at wavelengths from 0.5 to 10 microns, for a primary aperture of 3.8m, and a secondary diameter of 0.95m. Measured MTF at 0.5 to 4 microns for UKIRT optics is compared with aperture diffraction MTF, including the effect of average seeing conditions. Wavelength dependent MTF under good atmospheric seeing conditions, i.e. 0.5, 1, and 2 arcsec seeing, are presented with point spread functions. Performance matches predictions. The theory of MTF is introduced. It measures the modulation or contrast of features in the exit pupil at various spatial frequencies and expresses them in linear or angular separation distances.