谷歌Nexus 9智能终端原始GNSS观测值的质量分析

从信噪比、伪距残差、相位残差等方面对开阔环境下的静态谷歌Nexus 9智能平板终端的原始全球导航卫星系统（Global Navigation Satellite System，GNSS）观测数据质量进行了分析评估，结果表明，Nexus 9平板的全球定位系统（Global Positioning System，GPS）、GLONASS观测值的信噪比比测量型接收机低10 dBHz左右；伪距精度分别为5.43 m、11.39 m，相位精度分别为4.44 mm、4.99 mm；相对于高度角来说，信噪比与伪距残差的相关性更强，更能反映观测数据的质量。在此基础上给出了信噪比定权的随机模型，并进行了开阔环境下的伪距单点定位测试。实验结果表明，基于信噪比定权的单点定位平面精度为2.74 m，高程精度为4.56m，比高度角定权精度提高了约26%。

Quality Analysis of Raw GNSS Observation of Google Nexus 9 Smart Tablet Terminal

This paper analyzes and evaluates the quality of the static raw Global Navigation Satellite System (GNSS) observations of Google Nexus 9 tablet in terms of signal-to-noise ratio(SNR), pseudorange residual and phase residual in the open sky. The results show that the SNR of Global Positioning System (GPS), GLONASS observations collected from the tablet is about 10 dBHz lower than normal surveying receiver; pseudorange accuracies of GPS, GLONASS observations are 5.43 m and 11.39 m, phase accuracies are 4.44 mm and 4.99 mm respectively. Compared with the elevation, the SNR is more relevant to the pseudorange residuals and reflects the quality of the observations better. On this basis, a stochastic model of SNR weighting is given and a standard point positioning test is conducted. The positioning precision is 2.74 m in horizontal component and 4.56 m in vertical component which are increased by about 26% compared with the elevation weighted positioning in the open sky.