一种基于数据库描述的电文参数通用解算方法

An universal method for calculating message parameters based on database description

卫星导航电文参数解算通常采用硬编码方式实现,电文格式、参数编排、参数系数等信息均内嵌在程序代码中,代码可读性、可维护性和可扩充性差。为解决基于超帧、主帧和子帧的固定帧结构的电文参数通用解算问题,提出了一种采用数据库描述电文帧格式、电文参数编排方式以及电文参数结果定制的方法。设计了电文参数通用解算算法以及时间阈值判断算法,通过数据库配置实现不同格式导航电文参数的解算,参数结果根据数据库配置控制输出。采用实际接收的电文进行了测试,结果表明,所提出的方法具有良好的通用性,正确解算了GPS LNAV电文、北斗D1电文和北斗D2电文等3种导航电文参数,电文参数解算实现100%覆盖,参数结果组合输出100%可配置,电文参数增加、删除和修改等完全自适应,避免了电文帧丢失、电文参数更新造成的同一组参数不匹配问题。

The calculation of satellite navigation message parameters is usually implemented by hard coding.The message format,parameter arrangement and parameter coefficients are embedded in the program code whose readability,maintainability,and scalability are poor.In order to solve the general solution problem of message parameters with fixed frame structure based on superframe,main frame and sub-frames,a method to describe the message format,message parameter arrangement mode,and message parameter result customization by using database is proposed.A general solution algorithm for message parameters and a time threshold judgment algorithm are designed.The solution of different format navigation message parameters is realized through database configuration,and the parameter result is controlled according to the database configuration.The proposed method is tested using the actual received message,and the results show that the method has good versatility and can correctly solve the three kinds of navigation message parameters(i.e.GPS LNAV message,BDS D1 message and BDS D2 message).The message parameter solution achieves 100%coverage,the parameter result combination output is 100%configurable,and the addition,deletion and modification of message parameters are completely adaptive,which avoids the mismatching of the same set of parameters caused by message frame loss and message parameters update.