海上移动平台GNSS可降水量反演影响因素研究

Research on precipitable water vapor inversion influencing factors of GNSS for offshore mobile platforms

基于海上移动平台GNSS动态精密单点定位技术(precise point positioning,PPP),对海洋上空可降水量(precipitable water vapor,PWV)探测的影响因素进行了研究,主要分析了采样间隔,卫星截止高度角,PPP解算方式(固定解或浮点解)以及有无北斗卫星系统组合对海洋PWV反演的影响。结果显示,采样间隔为30 s时,PWV反演的精度最高;可用卫星数较少的情况下,截止高度角设为5°~10°时,PWV反演精度更优,随着卫星截止高度角的增大,反演精度逐渐降低;定位解是否固定对PWV反演精度影响较小;在GPS GLONASS系统组合的基础上,加入北斗卫星观测值,将提高观测的冗余度,有利于PWV反演精度的提高。

Based on Global Navigation Satellite System(GNSS)dynamic precision point positioning technology(PPP),the influence factors of precipitable water vapor(PWV)detection over the ocean were studied.The sampling interval,satellite masking angle,PPP solution method(fixed solution or floating point solution),and the influence of Beidou satellite system combination on ocean PWV retrieval were mainly analyzed.In the marine observation environment,the results show that the accuracy of PWV inversion is the highest when the sampling interval is 30 s.When the number of available satellites is small,the accuracy of PWV inversion is better when the satellite masking angle is set to 5°-10°,and the accuracy decreases gradually with the increase of the satellite masking angle.Whether the PPP solution is fixed or not,it has little effect on the accuracy of PWV inversion.On the basis of GPS GLONASS system combination,adding Beidou observation value will improve the redundancy of observation and improve the accuracy of PWV inversion.