The Diffuse Infrared Background Experiment (DIRBE) is a cryogenically-cooled 10-band photometer with a large field-of-view (0.886 x 0.886 degrees2) which scans by rotation of the Cosmic Background Explorer about a spin axis. In-orbit calibration requires that the DIRBE detect and measure with precision the signatures of compact sources as they transit the field-of-view. Analysis of the conceptual optical design revealed that response of the 10 bands would vary significantly as a function of source position in the field-of-view, caused by anamorphic pupil distortion and field separation. The optical design reported in this paper is the result of changes which greatly improve the response uniformity and radiometric accuracy of the DIRBE.
B J Howell,
M E Wilson,
"Radiometric Accuracy Of The Diffuse Infrared Background Experiment (Dirbe)", Proc. SPIE 0445, Instrumentation in Astronomy V, (9 January 1984); doi: 10.1117/12.966159; https://doi.org/10.1117/12.966159