Abstract: A method for determining bit boundary of a navigation bit of a satellite signal received by a receiver is disclosed. The method includes dividing an assumed navigation bit equally into a plurality of power units, calculating unit powers of each of the plurality of power units, and determining a plurality of phases. Each of the plurality of phases is associated with an estimated bit boundary. The method further includes adding unit powers of the plurality of power units to obtain a plurality of bit powers. Each of the plurality of bit powers corresponds to the estimated bit boundary associated with one of the plurality of phases. The bit boundary of the navigation bit is determined based on the plurality of bit powers.

Abstract: A method for detecting a false lock of a carrier tracking loop is described. The method includes obtaining an average output of each of one or more loop discriminators in a predetermined time period when the carrier tracking loop works in a first mode; and determining whether the carrier tracking loop is falsely locked when the absolute value of the average output of any of the one or more loop discriminators is greater than a respective threshold associated with the corresponding loop discriminator. The carrier tracking loop comprises the frequency-locked loop and the phase-locked loop in the first mode. The one or more discriminator loops may include a frequency-locked discriminator loop, a phase-locked discriminator loop, or a combination thereof.

Abstract: A method for correcting errors for an Inertial Navigation System. The method includes the steps of determining a working state of the Inertial Navigation System based on a current positioning parameter of the moving object, a navigation map-based reference positioning parameter and a GPS-based reference positioning parameter, and replacing an initial parameter of the Inertial Navigation System with the GPS-based reference positioning parameter and resetting the Inertial Navigation System to an initial state if the Inertial Navigation System is determined to be in an abnormal working state.