2002 · 23 citations · 0 references
Natural SciencesAstronomyEarth SciencesRadio AstronomyRemote SensingStellar AstronomyRadiometric CalibrationSatellite Data CalibrationSatellite Data ValidationSatellite Image InterpretationSatellite InstrumentationSatellite SensorsAbsolute CalibrationAbsolute Radiometric CalibrationCalibration Stability AssessmentCalibration TechniquesCelestial PhysicsLong-term StabilityReflectanceVicarious Calibration
Radiometric calibration of remote sensing satellites has traditionally been accomplished by means of vicarious ground calibration techniques. These methods employ extensive modelling algorithms to describe the ground reflectance, atmospheric absorption, etc. The agile-body IKONOS satellite has the capability to maneuver the vehicle such that celestial scenes can be imaged. Hence, several radiometrically characterized stellar sources have been imaged, on three separate occasions at one-year intervals. The data has been used to develop a radiometric calibration that simply correlates the detector counts in the imagery to the energy presented at the telescope aperture. While the results do not yet fully agree with vicarious ground calibration techniques, the stellar data is highly repeatable, easily predictable, the collection activities are easily scheduled and repeatable, and the results extremely linear. This method has established excellent long-term stability. It promises future absolute radiometric calibration. 1.1 Historical Background 1.