| Based on the rapid development and progress of modern science and technology,as well as the actual needs of engineering construction,the application of precision measurement technology has been reflected in many fields,especially the application of precision ranging technology and high-precision time synchronization technology.In the military field,high-precision ranging technology is needed to determine the trajectory of the missile;In the field of UAV cooperative operation,it is necessary to determine the relative position of each cooperative operation unit and unify the operation time.With the wide application of global satellite navigation system,more and more projects choose this system for time synchronization.In the military field,excessive reliance on this system can easily lead to losing the initiative in war;In the field of UAV cooperative combat,once the combat environment is not conductive to the system,it is likely to lead to mission failure.Therefore,this thesis introduces a ranging and time synchronization technology——Dual One-Way Ranging(DOWR)technology,which can complete the ranging and time synchronization system between terminals without the help of satellite navigation system.At the same time,this thesis introduces the carrier phase smoothing pseudo range algorithm to further improve the ranging accuracy of the system.The main research content of this thesis is to design and implement a dual ranging and time synchronization(Dual Ranging and Time Synchronization,DRTS)system based on FPGA development platform and DOWR technology.At the same time,the carrier phase smoothing pseudo range algorithm is used to improve the measurement accuracy of the system.The target accuracy is that the ranging error is less than 30 cm and the time synchronization error is less than 1ns.In the introduction part,we first introduce the source,background and significance of the subject,then introduce the related aspects of the subject and the research status of related technologies at home and abroad,and finally introduce the key research content and structure of this thesis.In the part of theoretical analysis,the principle of DOWR technology is introduced firstly,and then several aspects that may cause errors are analyzed.In order to eliminate or reduce these errors,the direct sequence spread spectrum communication system is further introduced,and the basic principle of the system is briefly introduced.Finally,the basic principle of carrier phase smoothing pseudo range algorithm is introduced,and the algorithm model of using the algorithm to improve the ranging accuracy is proposed.In the hardware implementation part,this thesis first introduces the hardware implementation platform combined with the application environment and parameter indicators,and then realizes the transmitter and receiver in turn,including the design of frame structure and source generation module,spread spectrum modulation module,carrier modulation module,digital to analog conversion module,analog to digital conversion module,spread spectrum code synchronization module,carrier synchronization and tracking module.The data interaction between the two terminals is completed.Finally,the carrier phase smoothing pseudo range algorithm module is implemented to reduce the error of pseudo code ranging value.In the system verification part,the system first carries out data processing,extracts the time and carrier phase information from the demodulated information of the receiver,and then carries out the equipment delay calibration.The next step is the performance verification of the system,mainly to verify the accuracy of ranging and time synchronization,and then uses the carrier phase smoothing pseudo range algorithm to smooth the pseudo code ranging value.Finally,the conclusion is drawn. |
