A SYSTEM FOR DETERMINING A VELOCITY AND A NAVIGATION SYSTEM

摘要

A vehicle navigation system is provided for determining navigation information relating to a vehicle. The vehicle navigation system comprises a system for determining a velocity of the vehicle, including a Doppler radar system arranged to transmit a signal towards a target and to receive a reflected signal from the target. The Doppler radar system comprises an in-phase parameter determiner that is arranged to provide an in-phase parameter based on the transmitted and reflected signals, and a quadrature parameter determiner that is arranged to provide a quadrature parameter based on the transmitted and reflected signals. The velocity determining system also comprises a processing system arranged to determine the velocity of the vehicle by performing a calculation in the time domain based on the in-phase parameter and the quadrature parameter. The vehicle navigation system may also comprise an inertial navigation system arranged to receive the determined vehicle velocity, or distance information derived from the determined vehicle velocity, and to use the determined vehicle velocity or the distance information to determine the navigation information.