One of the objectives of CLARREO Pathfinder mission is to demonstrate on-orbit data matching for sensor inter-calibration The CLARREO Pathfinder approach for reference inter-calibration is based on measuring spectral reflectance with high accuracy and establishing an on-orbit reference for operating Earth viewing sensors: CERES and VIIRS on JPSS. The mission goal is to be able to provide CLARREO reference observations that are matched in temporal and angular domains with measurements from the aforementioned instruments, with sampling sufficient to overcome the random error sources from imperfect data matching. The inter-calibration method is to monitor changes in targeted sensor response function parameters: effective offset, gain, nonlinearity, spectral response function, and sensitivity to polarization. In this paper, we focus on estimating uncertainty for inter-calibration of imaging sensors such as VIIRS.