精密单点定位(PPP)模糊度固定方法有3种:星间单差法、整数相位钟法和钟差解耦法,但目前仅法国CNES公开发布用于整数相位钟法PPP模糊度固定的产品,因此研究基于整数相位钟法的用户端PPP模糊度固定模型很有必要.本文分析了整数相位钟法PPP模糊度固定模型,着重指出该模型与传统浮点解PPP模型的区别;提出一种顾及质量控制的逐级模糊度固定策略用于具体实施PPP模糊度固定.大量动态PPP解算试验表明:与浮点解PPP相比,固定解PPP具有更快的收敛速度且定位精度和稳定性更好.
Three representative precise point positioning (PPP) ambiguity fixing methods have been developed, which include the single-difference between-satellite method, the integer phase clock method and the decoupled clock method. Currently, only the French CNES published products applied to PPP ambiguity fixing using the integer phase clock method. Therefore, it is necessary to study the client PPP ambiguity fixing model based on integer phase clock method. This paper analyzes PPP ambiguity fixing model based on the integer phase clock method, and highlights the difference between the ambiguity-fixed PPP model and the traditional ambiguity-float PPP model. A cascaded ambiguity fixing strategy is proposed to perform PPP ambiguity fixing with special regard to quality control. Numerous kinematic PPP experiments show that ambiguity-fixed PPP can obtain a fast convergence, a better and stability positioning accuracy, compared with ambiguity-float PPP.
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