高光谱观测卫星高精时间同步方案设计与应用

为了满足星上高光谱相机、全谱段光谱成像仪、星敏感器等时间精度敏感仪器的高精度时间同步需求,高光谱观测卫星上设计了可适应多种精度需求的时间同步方案。对于系统时间,综合通过星地时差集中校时、均匀校时、GPS总线校时、GPS硬件秒脉冲校时等校时方法进行时间修正；对于终端用户,分别给出直接采用广播的进行本地时间修正的时间同步方法、采用广播及内部秒脉冲的时间同步方法、采用广播授时和不同秒脉冲校时方案的地面时间重建算法。利用在轨数据,对卫星星敏感器、全谱段光谱成像仪及可见短波红外高光谱相机的曝光时刻时间重建方法进行了应用说明,并对不同方法的时统误差进行了分析。

Design and Application of High Precision Time Synchronization Scheme for GF-5 Satellite

In order to satisfy the high precision time synchronization demand of multiple hyperspectral payloads, full-spec. tral payloads, star sensors and other high time sensitivity products on the GF-5 satellite, a high precision time synchroniza.tion method is proposed. The time synchronization method incorporates the telemetry measurement and adjustment, GPS bustiming, bus broadcasting timing and GPS hardware pulse per second method, accommodating the general precision and highprecision time synchronizing application scene. The time re-build algorithm of bus broadcasting timing and multiple pulse per second is given. Using the in-orbit data, the time re-build method of star sensors, Visible and Infrared Multispectral Im.ager and Advanced Hyperspectral Imager are given as examples. The time synchronization accuracy is analyzed.