Operation of In-situ Optical Instruments Calibration Laboratory

Abstract

After the launch of GOCI (Geostationary Ocean Color Imager) in 2010, KOSC has been performed the in-situ observations for vicarious calibration and measured the optical characteristics of the in-situ instruments, such as Analytical Spectral Devices FieldSpec3, TriOS and RAMSES. Because the vicarious calibration depends on the collection of ground truth data, in-situ spectroradiometers should be calibrated each time in the laboratory. The optical laboratory in KOSC (Korea Ocean Satellite Center) has established for three aspects. The first is the optical performance characterization of the in-situ ocean optical instruments such as ASD Fieldspec Spectroradiometer. The second is the quantification of the variation between before and after field work, and the last is the relative correction of them. The laboratory is equipped with a 20 inches integrating sphere (USS-2000S, LabSphere) and KRISS (Korea Research Institute of Standards and Science) calibration lamp (Tungsten Halogen, 250~1050 nm) that are traceable to the National Institute of Standards Technology (NIST-traceable) for the standard light source, a reference spectrometer (MCPD9800, Photal) for the relative calibration, and an optical table having a flatness of ± 0.1 mm. In this study, we suggest that the continuous monitoring of the in-situ instruments should be performed for more accurate calibration and validation of GOCI. The ASD instruments, calibrated i Devices FieldSpec3, TriOS and RAMSES. Because the vicarious calibration depends on the collection of ground truth data, in-situ spectroradiometers should be calibrated each time in the laboratory. The optical laboratory in KOSC (Korea Ocean Satellite Center) has established for three aspects. The first is the optical performance characterization of the in-situ ocean optical instruments such as ASD Fieldspec Spectroradiometer. The second is the quantification of the variation between before and after field work, and the last is the relative correction of them. The laboratory is equipped with a 20 inches integrating sphere (USS-2000S, LabSphere) and KRISS (Korea Research Institute of Standards and Science) calibration lamp (Tungsten Halogen, 250~1050 nm) that are traceable to the National Institute of Standards Technology (NIST-traceable) for the standard light source, a reference spectrometer (MCPD9800, Photal) for the relative calibration, and an optical table having a flatness of ± 0.1 mm. In this study, we suggest that the continuous monitoring of the in-situ instruments should be performed for more accurate calibration and validation of GOCI. The ASD instruments, calibrated i