camera calibrations and more! mrcal is a photogrammetry toolkit that provides improved methods for making and using camera models (calibration, tracking, mapping, etc). Currently the focus is on calibration and uncertainty propagation, but more methods will be added with time. It was originally built at NASA/JPL to generate the high-accuracy calibrations demanded by long-range stereo, so it provides facilities to analyze calibration accuracy and to propagate and report uncertainties.