Radiometric characterization of the ROCSAT Ocean Color Imager

The Ocean Color Imager (OCI), a multispectral optical imager for observing pigment distributions in low-latitude oceans, has been successfully built a nd parameterized. To recover at-sensor radiance data, a mathematical model was developed to characterize its radiometric response; the corresponding p arameters were identified initially by pre-flight calibration and were adap ted in-flight by a method of cross-platform calibration. The cross-platform in-flight calibration was carried out to compare radiance data with data m easured by the vicarious orbital sensor at the cross points to determine po ssible changes in the parameters and performance of the OCI. The radiometri c model, the pre-flight parameters and the method of cross-platform in-flig ht calibration are reported here.