针对WAAS等传统的广域差分方法存在DOP值太大和要求基准站时间严格同步等问题,提出了星钟和星历误差相对分离的广域差分新方法。提出的相对分离理论包括以所有卫星的广播星历为基准的星钟误差的相对分离,以各卫星星钟误差相对分离结果为基准的相对星历误差分离和固定偏差的星钟二次修正三部分,其可简单归纳为星钟-星历-星钟的修正思路。这种方法除无需基准站同步外,用户定位比WAAS准。理论论证和算例仿真证明这种理论是科学的,对建设各种卫星导航系统的差分增强系统均是适用的。
Armed at the problems of the great dilution of precision (DOP) value and strict time synchronization among differential reference stations in Wide Area Augmentation system (WAAS) et at. traditional wide area differential method, a novel wide area differential method based on the relative separation between satellite clock errors and satellite ephemeris errors. The relative separation theory presented includes three parts: the separation of satellite clock errors relative to broadcast ephemeris, the separation of satellite ephemeris errors relative to that of satellite clock errors and the second correction on the fixed difference due to no correction of the reference satellite. It can be summarized as the corrective thought of satellite clock-satellite ephemeris-satellite clock. Besides no necessity of strict time synchronization among differential reference stations, this method can obtains more accu- rate user position than WAAS et at. It has proved to be scientific by theoretical and instance argumentation, and to be suitable for all kinds of wide area differential systems suited to satellite navigation systems.