Patent ID: 7408504
Filing Date: 2008-08-05
Classification: G01S

Abstract:
1. A GPS position measuring method in which a receiver terminal receives a signal from a satellite and calculates pseudorange between the satellite and the receiver terminal by capturing a portion of the received satellite signal having predetermined time duration, comprising the steps of: obtaining a predetermined number of first input signals, each having a length equivalent to one bit of navigation data, from the received satellite signal of predetermined time duration directly sent from the satellite and directly received by the receiver terminal, and using a plurality of delays of the beginning of data processing with spacing of the delays being small relative to the duration of a navigation data bit; synchronous summation of the first input signals to make second input signals; a polarity modifying calculation process in which a pseudopattern prepared by the receiver terminal is applied to the second input signals to homogenize the polarity of the navigation data bits; synchronous summation of the signals obtained by the polarity modifying calculation process from the received satellite signals having predetermined time duration; correlation calculation of the obtained synchronous summation signals and a replica PN code prepared by the receiver terminal; detecting the signal delay value by using the results of the correlation calculation; and calculating the pseudorange by using the delay value.