城市典型场景下低成本GNSS RTK定位性能评估与分析

Evaluation and Analysis of Low-cost GNSS RTK Positioning Performancein Typical Urban Environment

随着大众应用位置服务的快速发展,低成本GNSS的高精度定位越来越被重视。低成本GNSS接收机也从早期的单频观测逐渐向双频过渡。在开阔环境下,低成本单、双频RTK的固定率较高,且能够达到厘米级定位精度,但对于观测环境复杂多变、卫星信号遮挡和干扰严重的城市典型场景,低成本GNSS RTK定位性能到底如何,相关的评估却不多。基于此,采用梦芯T906B和u-blox ZED-F9P低成本双频接收机,从模糊度固定率、定位精度两个方面评估和分析了开阔、半遮挡、遮挡等场景下低成本单频和双频GNSS RTK定位性能及差异。实测数据结果表明:开阔环境下单频和双频性能相当;在半遮挡环境下,双频较单频模糊度固定率提升约10%~20%,定位精度提升约10%~50%;在遮挡环境下,双频较单频模糊度固定率提升约10%,定位精度提升约10%~30%。

With the rapid development of mass application location services,high-precision positioning of low-cost GNSS has been paid more and more attention.Low-cost GNSS receivers have gradually transitioned from early single-frequency observations to dual-frequency observations.Generally speaking,in an open environment,low-cost single-frequency and dual-frequency RTK have a higher fixation rate and can achieve centimeter-level positioning accuracy.However,for typical urban scenes where the observation environment is complex and changeable,satellite signal obstruction and interference are severe,and the low-cost GNSS RTK positioning performance is not much related to evaluation.Therefore,this paper uses Mengxin T906B and u-blox ZED-F9P low-cost dual-frequency receivers to evaluate and analyze the low-cost single-frequency and dual-frequency GNSS RTK positioning performance and differences from the two aspects of ambiguity fixed rate and positioning accuracy,in open,semi-obstructed,and occluded scenarios.The measured data results show that the single-frequency and dual-frequency performances are equivalent in an open environment;in a semi-occluded environment,the dual-frequency ambiguity fixed rate is increased by about 10%~20%,and the positioning accuracy is increased by about 10%~50%;In an occluded environment,the ambiguity fixed rate of dual frequency is increased by about 10%compared with that of single frequency,and the positioning accuracy is increased by about 10%to 30%.