The Challenges of 1% Uncertainty in Optical Ground Support Equipment Calibrations

Measurement requirements for earth observation missions are driving towards <2% uncertainty on orbit for long term studies and data collection to enable predictive modeling of climate change. This demand for low uncertainty on orbit directly translates to unprecedented <1% uncertainty budgets on Optical Ground Support Equipment (OGSE) for calibration prior to launch. Basic challenges include meeting radiance levels, dynamic ranges, uniformity, and absolute traceable monitoring levels. Advanced challenges for emerging instrument architecture include image quality assessment, spatial and spectral characterization, spectral line and in-band quantum efficiency (Hyperspectral), and sensor fusion (0.3-14um) calibrations. Every aspect of these test systems, including normally relativistic characterization like Uniformity measurements, will require a new level of assessment for uncertainty. We will discuss the challenges and solutions for meeting the requirements for several recent space and terrestrial programs, and the new techniques needed to take programs to the levels of uncertainty required by the EOS community.