基于北斗降维双差模型的舰艇快速定姿算法研究

Research on fast warship attitude determination algorithm based on beidou dimensionality reduction double difference model

根据北斗GEO卫星的特殊星座构型,提出一种基于北斗降维双差模型的舰艇快速定姿算法。根据北斗GEO卫星的特点,在初始定位误差较小的情况下,忽略z轴误差带来的影响,建立降维双差模型。利用B_1和B_2频点形成宽巷组合,根据初始伪距值计算宽巷模糊度初始值,并解算基线向量候选值;通过模糊度函数法对候选值进行判决,得到最优基线向量,解出宽巷模糊度;最后以得到的最优基线向量为初始基线向量,利用B_1频点观测值形成2个双差观测方程,解算B_1频点模糊度,进行舰艇定姿。利用北斗实测数据进行仿真验证,结果表明该方法解算B_1频点模糊度成功率高,确定的航向角标准差为0.16°,纵摇角标准差为0.07°,是一种高效快速的舰艇定姿算法。

According to the special constellation configuration of BeiDou GEO satellite, a fast ship Attitude Algorithm which is based on Beidou dimension reduction and double difference model was presented in this paper. According to the characteristics of BeiDou GEO satellites, if the initial position error is small, the effects caused by the z-axis error could be ignored, and dimensionality reduction double difference model could be established. B1 and B2 frequency points were com- binated to form wide lane, and calculate the initial value of wide-lane ambiguity according to the initial value of the pseudorange, and the candidate value of baseline vector can be calculated; the optimal baseline vector is obtained by judging the candidate value with ambiguity function method, and the wide lane ambiguity can be solved. Finally, the aforementioned optimal baseline vector is taken as initial baseline vector, two double difference observation equations are formed by B1 frequency point observations for B1 frequency ambiguity, and warship attitude is determined. The simulation example of BeiDou actual measurement shows that success rate of solving B1 frequency ambiguity is high, the standard deviation of heading angle and pitching angle are 0.16° and 0.07° respectively, so the method is of high-efficiency and speediness.