Positioning device

The objective of the present invention is to provide a technology able to increase speed precision by correcting errors in a mobile-body-side built-in clock in a positioning device of a mobile body such as a vehicle. The positioning device is provided with: an embedded clock error estimation unit (123) that estimates as an embedded clock error the error of a vehicle-side built-in clock on the basis of the difference between a delta range and a calculation range rate; and a range rate estimation unit (125) that, on the basis of the vehicle position and the position and speed of a GPS satellite that is on the basis of a transmitted signal, estimates a stopping range rate and corrects the calculation range rate on the basis of the built-in clock error. Also, the positioning device is provided with a selfsame-vehicle speed calculation unit (127) that, on the basis of a navigation matrix, the stopping range rate, and the corrected calculation range rate, calculates the selfsame-vehicle speed (V) pertaining to each of three axis directions forming an orthogonal coordinate system.