Navigation tool

(57) Summary book invention is navigation equipment combined with a display device, At least two sensor elements combined with a detection means to be at least two sensor elements which have a relative position which receives mutually known, and to record change of the parameter each sensor element was beforehand decided to be, It is related with navigation equipment equipped with the computer means which calculates the direction and speed of change recorded based on the time required between a timing means to determine the time of change with each sensor element, and change recorded as the relative position of the sensor element.