In navigation, dead reckoning is the process of calculating current position of some moving object by using a previously determined
position, or fix, by using estimations of speed, heading direction and course over elapsed time. [..] Dead reckoning is subject
to cumulative errors. Advances in navigational aids that give accurate information on position, in particular satellite navigation
using the Global Positioning System, have made simple dead reckoning by humans obsolete for most purposes. However, inertial
navigation systems, which provide very accurate directional information, use dead reckoning and are very widely applied. [..]
In marine navigation a "dead" reckoning plot generally does not take into account the effect of currents or wind.
Aboard ship a dead reckoning plot is considered important in evaluating position information and planning the movement of
the vessel.
https://en.wikipedia.org/wiki/Dead_reckoning (November 2020)