Research On Improving Ranging Precision Method In Dual One-way Ranging And Time Synchronization System

With the continuous and rapid development of such scientific research field asaerospace test, global satellite navigation system, mobile communication and electricpower, etc., the significance of precision ranging and time synchronization system hasbeen increasing highlighted. More and more engineering and scientific research fieldrequire precision time synchronization system to be as a benchmark. For instance,time centers and time laboratories around the world need high-accuracy timesynchronization; the atomic clocks of satellite launch, satellite observation and controland test ranging need to be calibrated; high-precision baseline measurement and timesynchronization is needed between satellites, ground stations, and between satelliteand ground station. Besides, AFF and networked aircrafts also need high-precisionbaseline measurement and time synchronization.Therefore, the study of Dual One-way Ranging and Time SynchronizationSystem is of great significance to the scientific research fields mentioned above. Onthe basis of DRTS, this paper is mainly focuses on two kinds of methods to improvethe measurement precision of DRTS, which are the technology of carrier phasesmoothed pseudo-range and calibration of transceiver delay. The main contents andresults of the study are as follows:1) From the perspective of signal processing algorithm, this paper discussedhow to increase the accuracy of DRTS through improving the preprocessing method.For such ranging errors as unexpected pseudo-code mistake and carrier phase leap,this paper discussed that use the last smoothed result as the current smoothed result,which ensured the ranging accuracy of the system. According to the principal ofcarrier phase smoothed pseudo-range and the real-time requirement of DRTS, thispaper presented and simulated the algorithm of DRTS carrier phase smoothedpseudo-range, which was verified as effective by using the data obtained bylaboratory. The simulation results show that, under the simulation condition, thepseudo-range error was greatly improved after smoothing (when M=300, the RMS ofpseudo-range error decreased to0.9389after smoothing). However, the smoothinglength should be chosen by weighing the smoothing effect and the real-timerequirement. In this paper, both the ranging accuracy and real-time property fulfilled the system when M=200~300, which provides theory basis for DSP implementationof DRTS.2) DRTS is established based on the principal of Dual One-way Ranging, thetime delay of the signal transmitter and receiver are concluded in the ranging andtiming measurements, which greatly influence the accuracy and performance ofDRTS. Therefore, based on a new definition of transceiver delay, this paper presents amethod of calibration for DRTS, and the verification of this method is also presented.The measurements show that the accuracy achieves the order of nanosecond, whichprovides an effective reference for dual one-way ranging and time synchronizationsystem.