Abstract
The Independent Calibration (IndCal) approach for the CLARREO Pathfinder (CPF) mission HySICS instrument targets SI-traceable absolute radiometric calibration at the sub-percent level. As a major element of IndCal, a physics-based endto- end instrument model of HySICS has been developed to predict spectral and radiometric behavior.
As part of HySICS pre-launch characterization, detector-based absolute radiometric calibration was performed using the NASA Goddard’s GLAMR, which is a tunable laser-based calibration system covering the 340–2500 nm spectral range. In this study, model predictions are compared with GLAMR measurements and other pre-launch component- and system-level calibration results. Special emphasis is placed on the effects of the dual-zone grating configuration and their impact on calibration. The comparison also reveals several instrument design and calibration sensitivities to instrument parameters.
Overall agreement between modeled and measured responses supports the use of physics-based instrument modeling to predict and evaluate radiometric performance, identify calibration risk areas, validate pre-launch calibration results, and support CPF on-orbit calibration planning when applicable. The comparison also highlights the instrument parameters and measurements that most strongly limit model fidelity, helping define characterization priorities and define uncertainty budget for future SI-traceable hyperspectral sensors.
Radiometric Modeling and GLAMR Comparison for CPF HySICS Independent Calibration
The Independent Calibration (IndCal) approach for the CLARREO Pathfinder (CPF) mission HySICS instrument targets SI-traceable absolute radiometric calibration at the sub-percent level. As a major element of IndCal, a physics-based endto- end instrument model of HySICS has been developed to predict spectral and radiometric behavior.
As part of HySICS pre-launch characterization, detector-based absolute radiometric calibration was performed using the NASA Goddard’s GLAMR, which is a tunable laser-based calibration system covering the 340–2500 nm spectral range. In this study, model predictions are compared with GLAMR measurements and other pre-launch component- and system-level calibration results. Special emphasis is placed on the effects of the dual-zone grating configuration and their impact on calibration. The comparison also reveals several instrument design and calibration sensitivities to instrument parameters.
Overall agreement between modeled and measured responses supports the use of physics-based instrument modeling to predict and evaluate radiometric performance, identify calibration risk areas, validate pre-launch calibration results, and support CPF on-orbit calibration planning when applicable. The comparison also highlights the instrument parameters and measurements that most strongly limit model fidelity, helping define characterization priorities and define uncertainty budget for future SI-traceable hyperspectral sensors.