タイトル | APART/PADE analytical evaluation of the diffuse infrared background experiment for NASA's cosmic background explorer |
著者(英) | Breault, R. P.; Evans, D. C. |
著者所属(英) | Sachs/Freeman Associates, Inc.|Breault Research Organization |
発行日 | 1984-01-01 |
言語 | eng |
内容記述 | The stray light performance of NASA's Diffuse Infrared Background Experiment (DIRBE) has been calculated using the APART/PADE code. That code has been upgraded to handle off-axis optical systems such as DIRBE. Under observing conditions, sunlight is attenuated by 21 to 29 orders-of-magnitude; uniform diffuse illumination, by 6 to 9 orders of magnitude. The sunlight is attenuated by multiple diffraction at an external sun shield and by a forebaffle at the entrance to the DIRBE. Stray light is nearly a linear function of the Bidirectional Reflectance Distribution Function (BRDF) of the primary mirror at all wavelengths - or it can be made to be so by reducing the size of the field defining stop from 0.866 to 0.7 degrees square. For uniform diffuse illumination, half of the stray radiation comes from within 5 degrees of the center of the field-of-view. Particulate contamination of the primary mirror is expected to be a problem and special polishing and cleaning procedures are recommended - before mirror overcoating and again before flight. |
NASA分類 | SPACECRAFT INSTRUMENTATION |
レポートNO | 86A15392 |
権利 | Copyright |
URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/387597 |