A qualitative term describing the spread of obtained measured values. A high precision data set has small uncertainties associated with random effects. This says nothing about uncertainties associated with systematic effects. Quantitative information is provided in the associated uncertainty.
This term refers to a systematic transformation of the latitudes and longitudes of locations on the surface of a sphere or an ellipsoid into locations on a plane. Different transformations have been developed and they vary in terms of the priorities they assign on the conservation of angles, area, or distance and on the region of the globe they are optimized for. Projection results in gridded satellite measurements in a specific type of projection.