实时VLBI处理机技术

Real-Time Correlator Technologies of VLBI

实时处理机是探月工程VLBI测轨分系统数据处理中心的核心设备。软件处理机是自主开发的实时并行信号处理软件,运行于CPU+GPU结构的高性能集群服务器平台,硬件处理机是基于大规模FPGA器件研制的专用高速信号处理机。它们采用FX型结构,具备数据实时接收、解码、相关处理、相位校正信号提取、实时监视等功能。当探测器预报时延模型精度不够时,处理机系统可通过特殊的条纹搜索功能,现场实时自主重构高精度时延模型,引导处理机完成探测器信号相关处理。经过工程验证,月球探测器VLBI测定轨的总实时数据速率达到了512 Mbps。

Real-time correlator is the core facility of data processing center of China’s Lunar Exploration Project(CLEP)VLBI subsystem.Software and hardware ones are developed to ensure the successful tracking in all CLEP missions by the main and standby operation mode.The software correlator is a specially designed parallel computing program which runs on a high performance cluster server platform.The hardware one is a special high speed signal correlator based on a FPGA platform.They all adopt FX type structure,with real-time data receiving,decoding,correlation processing,phase correction signal extraction,real-time monitoring and other functions.When the accuracy of the prediction delay model is not enough,the correlator can reconstruct the delay model automatically by the special fringe search module and the processor is guided to complete the related processing of the detector signal.After engineering verification,the real-time data rate of the Lunar probe VLBI measurement orbit reached 512 Mbps.