Root mean square error (RMS)
A means of expressing the variability of a measurement in one dimension – by summing the squares of the errors, dividing by the number of observations and taking the square root. In this one-dimensional case, the RMS error is also an estimate of the standard deviation of the errors.
Source: Nick Ward, Vicechair, IALA e-Nav Committee, March 2009
Root Mean Squared
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM