基于MLAMBDA的BDS/GPS单频RTK性能分析

GNSS RTK技术以其高精度、高效率、实时性的优点，被广泛应用于航空航天等领域.目前双频RTK技术已非常成熟并且应用较广.相比于双频，单频GNSS RTK在数据质量控制、定位误差处理等方面存在难点.因此单频RTK服务精度可能会受到限制，其定位性能有待研究.本文基于扩展卡尔曼滤波模型，通过MLAMBDA模糊度搜索方法和Ratio检验法，结合实测数据，对比分析BDS，GPS，BDS/GPS三种模式下的单频RTK定位性能.实验证明在静态场景下，三种模式的单频RTK定位精度都在厘米级，可满足高精度定位需求；动态场景下三种模式的模糊度固定率都在70%以上，可满足日常定位需求.在静态及动态应用场景下，北斗的模糊度固定率最高，模糊度解算所用时间短，能实现快速RTK定位. 

Performance Analysis of BDS/GPS Single Frequency RTK Based on MLAMBDA Method

GNSS RTK technology is widely used in aerospace,high-precision mapping,transportation and other industries due to its high precision,high efficiency and real-time performance.At present,dual-frequency RTK technology is very mature and widely used.Single-frequency GNSS RTK has difficulties in data quality control and positioning error processing.Therefore,the accuracy of single-frequency RTK service may be limited,and its positioning performance remains to be studied.Based on the extended Kalman filter model,the MLAMBDA ambiguity search method and the ratio test method are combined with the measured data to compare and analyze the singlefrequency RTK positioning performance of BDS,GPS and BDS/GPS.The results show that the single-frequency RTK positioning accuracy of the three modes is in the centimeter level in the static scene,which can meet the high-precision positioning requirements.In the dynamic scene,the ambiguity fixed rate of the three modes is above 70%,which can meet the daily positioning requirements.Regardless of static or dynamic application scenes,BDS has the highest fixed rate of ambiguity,and the time used for ambiguity resolution is short,which can enable fast RTK positioning.