Research of Ambiguity Solution in CEI-based Orbit Determination

Connected-Element Interferometry (CEI) was a passive angular tracking method with the merits of high phase precision, flexible network distribution and nearly real-time processing due to short length of baselines. Firstly, feasibility of ambiguity solution in CEI-based orbit determination for GEO was analyzed. Integer ambiguity must be primarily solved in the orbit determination for TDRS because of its low initial orbit precision. It could be calculated by the high precise range measurement if the master control station could obtain range measurement, while the method of parameter estimation by fixing integer ambiguity was used without high precise range measurement. The simulation results indicated that this method was effective when the systematic error was less than 1.0m. The orbit determination precision for the satellite belt between 80°E and 140°E was gained, when the systematic error was 0.1m, along-track positional error component of the 110°E satellite reached 25 m, while 82m and 34m respectively for the 80°E satellite and 140°E satellite.