Patent ID: 7916076

Claim:
A method for calculating current position coordinate, applicable to a global positioning system (GPS) receiver, comprising: Step 1: searching for at least three satellites; Step 2: obtaining an ephemeris data of each of the at least three satellites at a first time point; Step 3: calculating a position coordinate of the GPS receiver at the first time point by utilizing the ephemeris data of each satellite; Step 4: calculating a position coordinate of each satellite at a second time point by utilizing the ephemeris data of each satellite, wherein the second time point is later than the first time point; Step 5: calculating a relative distance between the position coordinate of the GPS receiver at the first time point and the position coordinate of each satellite at the second time point; Step 6: evaluating a maximum moving distance of the GPS receiver from the first time point to the second time point; Step 7: calculating at least three distance ranges corresponding to the at least three satellites according to the respective relative distances and the maximum moving distance; Step 8: calculating a code delay of each satellite in the corresponding distance range to obtain the code delay of each satellite at the second time point; and Step 9: calculating the position coordinate of the GPS receiver at the second time point by utilizing the code delay at the second time point.