To obtain a Doppler positioning apparatus whose positioning and computing time can be reduced by a method wherein a measurement-acquisition- interval decision means decides the receiving interval of a Doppler frequency on the basis of the time change rate of the Doppler frequency.

An ephemeris reception means 1 receives an ephemeris which is transmitted periodically from a circling satellite which circles the earth, and a Doppler-frequency measuring means 2 measures a Doppler frequency at a time when the ephemeris is received. A Doppler-frequency-change-rate computing means 3 computes the time change rate of the measured Doppler frequency. A measurement-acquisition-interval decision means 4 decides the receiving interval of the ephemeris and the measuring interval of the Doppler frequency on the basis of the computed time change rate of the Doppler frequency. A weighting means 6 weights a computing expression which is used for a positioning and computing operation by a Doppler positioning and computing means 5 at an interval which is decided by an interval decision means 4. A truth-or-falsehood judgment means 8 judges the truth or falsehood of a received signal by using the Doppler frequency and the ephemeris of another satellite.