Time Frequency Unit Based On GPS Used For Lightning Detection

Although the lightning is a huge disaster for human world, it also can benefit us if theenergy can be used properly.Lightning location has important significance.The space-timealgorithm is used to caculate the spcace-coordinates of Lightning, that means an accuracyand stability time and frequency unit is necessary.The synchronization of multi-station has many methods.This thesis used a method ofGPS(Global Positioning system) time and frequent system.For the advantage of long timestability and it can cover the surface of the earth at any time and any weather, the GPS uses a1PPS(one pulse per second) to calibrate the1PPS’ which is generated by theVOCXO(Voltage Oven Controlled Crystal Oscillator).This meathod ensured the long timeand short time accuracy of the time&frequency between different lighting-location basestations.The main contents and result of this research as follows:(1) Analysis the common methods which are used in time&frequency synchronization.Improved the GPS time&frequency synchronization mehod, after elaborate the theory of it.Detailed designed the structure of this system.(2) Analysis the hardware by different modules, such as GPS module, VOCXO module,frequency-devide module, phase-detect module and so on. After that analysis the powersupply and signal integrity.(3) Analysis the software of this system, include MCU program and FPGA program.Elaborate the algorithm of Kalman-filter and PID. Simulation the phase-detect function ofthe FPGA by modlesim.(4) Set up a test system. Test the GPS time&frequency unit and analysis the testingresult.