BD2/GPS高精度同步时钟装置的设计与应用

Design and Application of High-Precision Time Synchronous Device Based on BD2/GPS

针对CCD(Charge Coupled Device)相机在探测脉冲激光光斑过程中曝光时刻与脉冲激光同步的问题,提出一种利用超前预测方式同步触发CCD相机抓拍光斑图像的高精度时钟源设计方案。该装置主要采用北斗2导航系统(BD2:BeiDou2 navigation satellite system)/全球定位系统(GPS:Global Positioning System),双模接收单元提供的协调世界时(UTC:Universal Time Coordinated)时间以及高精度秒脉冲(PPS:One-Pulse Per Second)时间基准作为同步时钟装置的基准源,并结合现场可编程门阵列(FPGA:Field-Programmable Gate Array)高速时序计算与微控制单元接口技术,保证CCD相机同步抓拍时间,从而完成高精度的同步触发。实验表明,该装置可以提供微秒级时间同步精度和标准授时信息,有效地缩短了CCD相机曝光时间,得到完整清晰的高信噪比脉冲激光光斑图像。

To deal with the problems of time and pulse lager synchronization in the process of CCD （ Charge Coupled Device） camera capturing laser spot images, an advanced forecasting method to trigger CCD camera synchronously to capture images of high-precision clock source is proposed. This device used the UTC（ Universal Time Coordinated ） and high-precision PPS （ one-Pulse Per Second ） as synchronous clock reference source provided by BD2 （ BeiDou2 navigation satellite system）/GPS （ Global Positioning System） dual-mode receiving unit . Ensured the synchronization capture time of the CCD camera in combination with high-speed FPGA （ Field-Programmable Gate Array ） computing and microprocessor interface timing technology, thus accomplished the synchronization trigger action. The experiment shows that this device can provide microsecond level synchronization accuracy and standard timing information, shorten the exposure time of the CCD camera effectively, get a complete clear pulse laser spot image with a higher SNR（ Signal-to-Noise Ratio） .