Phase 2 analysis of Spectralon material for use in on-board calibration systems for the medium-resolution imaging spectrometer (MERIS)

摘要

Abstract: This paper is a report on the ongoing flight evaluation testing of Spectralon, a diffuse reflectance material which is slated for use as a calibration panel for several satellite-based earth-observing instruments. The present study focuses on tests of the stability of the material under exposure to levels of UV/VUV radiation which match those of the low-earth orbit environment. In earlier UV/VUV exposure tests, some degradation of the optical properties of the material were observed; this optical degradation has been linked to photochemical degradation of organic contaminants. A more stringent manufacturing protocol was designed to eliminate these contaminants. The second phase of UV/VUV exposure testing, reported here, was undertaken with the object of validating and optimizing this new manufacturing protocol. Results of this testing indicate that the new manufacturing protocol yields a significant improvement in the optical stability of Spectralon under UV/VUV exposure. These results also indicate that most of the observed degradation is caused by exposure to radiation in the 200 - 380 nm band. This finding suggests new avenues of investigation, as well as providing justification for a simplification of future test requirements. !4