Research On Single Frequency GNSS RTK Algorithm With Cycle Slip Parameters

RTK is a widely used navigation and positioning technology.Due to its good realtime performance and high positioning accuracy,RTK is widely used in geodetic surveying,deformation monitoring,precision agriculture and other industries.With the rapid development of industries such as autonomous driving and robotics,the scope of application of RTK technology is further expanded,but the traditional dual-frequency receiver is costly,which limits the process of RTK technology promotion.Replacing the traditional receiver with a more cost-effective single-frequency RTK receiver is a trend to solve this problem,but the single-frequency RTK solution faces many problems,the most important of which is the cycle slip detection and ambiguity fixed for singlefrequency data.Single-frequency data cannot detect cycle slip by traditional linear combination method,and the use scene of single-frequency RTK tends to have poor observation environment and complex motion state,which further increases the possibility of cycle slip and the difficulty of cycle slip detection.Based on this background,the main work and conclusions of this paper are as follows:(1)Summarize the development status of satellite navigation technology and RTK technology,and clarify the necessity of the development of GPS and BDS combined single-frequency RTK technology in combination with the current situation of the industry.It is proposed that one of the key problems to be solved in single-frequency RTK technology is to detect the cycle slip of single-frequency data.(2)Combining the theoretical basis of RTK solution,starting from the basic satellite navigation theory,it introduces common errors,classical differential observations and combined observation construction methods,parameter estimation theory and integer least squares required for RTK solution.This prepares for later modeling.(3)Based on the analysis of the characteristics of cycle slip and the principle of commonly used single-frequency RTK cycle slip detection method,a single-frequency RTK solution model with cycle slip parameters is proposed,and the process and principle of model construction are described in detail.Experiments show that the single-frequency RTK solution performance of the model is no less than or better than the traditional singlefrequency RTK solution model.(4)On the basis of modeling the solution to calculate the parameters of the cycle slip real number,try to obtain the integer solution of the cycle slip parameter.Give the method of processing the cycle slip: If the cycle slip is an integer solution,repair the cycle slip,and if the cycle hop is a real solution,re-evaluate the ambiguity.Aiming at the problem that process the real number solution needs to re-evaluate the ambiguity that may reduce the accuracy of the solution caused,this paper combs the solution method of partial integer solution in integer least squares,and implements partial integer solution method based on descending correlation variance,which improves the repair rate of cycle slip.e weekly jump.Experiments show that the algorithm can detect the cycle slip in various situations,and it can achieve accurate repair for 88.87% of the cycle slip.After partial method,the cycle slip repair rate is increased to 90.42%.Moreover,the performance of the method of cycle slip detection is not affected by the number of satellites that have a cycle slip at the same time.After the method is used to repair or process the cycle slip,the performance and accuracy of the RTK positioning are not significantly affected by the cycle slip.