Optimization design of time synchronization system in ultraviolet limb imaging spectrometer

To improve the time synchronization precision of ultraviolet limb imaging spectrometer, the algorithm of clock drift rate calculation which was based on reference clock source was put forward. Firstly, the principle of limb time system was analyzed, then by using time tag unit of 1553B interface chip as clock reference source, the continual sample data was obtained and clock drift rate based on linear fit was calculated. Lastly, dynamic compensation of clock drift rate and optimization of limb system were realized. With using GPS time synchronization system, time synchronization system of high speed FPGA chip was designed, therefore dynamic changes of limb time synchronization errors were recorded by simulation and test equipment, furthermore limb time synchronization errors were measured dynamically. Time synchronization precision was measured. Experimental results indicate that time synchronization errors are no more than 13 ms for imaging beginning time error, the imaging finish time errors no more than 466.8 ms in different imaging time and no more than 362.5 ms in different integration time, which meets the demand of no more than 512 ms of qualification.