A method of estimating the position of a ship or aircraft by applying estimates of the distance and direction travelled to a previously known position. In respect to ships/boats, it excludes the effect of wind and current on the vessel. Compare with estimated position. Abbreviation: DR
{i} navigation by calculation; method of determining the position of a plane or ship by making a graph of its course and speed from a previously known position
calculating the position of a ship or aircraft without using the sun, moon, or stars