近年来,精密单点定位(PPP)模糊度固定技术不断发展,模糊度正确固定后可以提高短时间的定位精度。然而固定错误的模糊度,将引起严重的定位偏差,因此对PPP模糊度固定的成功率和可靠性进行研究很有必要。本文探讨了采用非差小数偏差(FCBs)改正的PPP模糊度固定方法;同时提出了一种分步质量控制的PPP部分模糊度固定(PAR)策略。通过欧洲CORS数据对该方法进行验证,结果表明:PPP模糊度固定可以提高小时解静态PPP定位精度。同时,采用部分模糊度固定策略,能够有效控制未收敛模糊度影响,提高用户端PPP模糊度固定成功率。
With the development of ambiguity resolution for precise point positioning(PPP) in recent years, it can improve positioning accuracy of PPP with short time observations since ambiguities can be fixed to right integers. However, unacceptable errors would be introduced into coordinate parameters if ambiguities are fixed to wrong integers. It's necessary to investigate the reliability and success rate of ambiguity-fixed PPP. This paper investigates PPP ambiguity fixing method based on zero-differenced fractional-cycle biases(FCBs). A partial ambiguity resolution(PAR) strategy based on cascaded quality control is proposed. Data sets from Europe CORS are used to validate and demonstrate PAR strategy. Results have showed that PPP ambiguity fixing can improve positioning accuracy of hourly PPP solution. When the strategy of PAR is applied, the influence of un-convergence ambiguities can be controlled efficiently and the success rate of PPP ambiguity fixing is improved.
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