Abstract:

Positioning based on time-delay measurement is one of the most important positioning method. The issue is focused on its usage on geosynchronous earth orbit satellite(GEO) measurement and determination. The principles, algorithm and diagram of positioning with four stations are presented. The equation of error’s transmission is derived here. The importance is the error analysis of how the position precision is affected by the measurement precision, the layout pattern of four stations, the length of the baseline, the precision of station’s position and so on. Monte-Carlo simulation is achieved on computer which is coincident with the result of the error analysis. The simulation result indicates that all the measurement precision, the layout pattern of four stations, the length of the baseline and the precision of station’s position are the key factors of the position precision; the layout like an inverse Y form is the best one, and a rectangle or diamond form is the worst layout form which is not suggested to be used in positioning system. In order to get precision with order of kilometer, the baseline is suggested to be larger than 1 000 km. It is more better if even more larger; the precision of station’s position must be better than 1 m.