Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2014 · 13 citations · 2 references
Natural SciencesMaterials EngineeringMaterials ScienceOptical MaterialsOpticsRemote SensingInfrared InstrumentationInfrared Optical MaterialsInfrared Remote SensingInfrared SpectroscopyNear-infrared SpectroscopyOptical SpectroscopyDirectional-hemispherical ReflectanceMeasurement Error ModelsRandom Error AnalysisReflectanceShortwave Remote SensingSystematic Error AnalysisSystematic Error CalibrationSystematic Error Correction
Methods for making total and diffuse directional/hemispherical reflectance measurements in the shortwave to longwave infrared using an integrating sphere are described. The sphere is a commercial, off-the-shelf optical device with its sample port at the bottom, which is essential for examining powdered samples without using a cover glass. The reflectance spectra of recently-developed National Institute of Standards and Technology (NIST, USA) infrared reflectance standards have been measured using the sphere. Reflectance spectra of other materials such as Spectralon and Infragold were also measured. The relative systematic error for the total reflectance measurements is estimated to be on the order of 3%, and random measurement error for multiple samples of each material is on the order of 0.5%.
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