star tracker attitude data

The satellite’s star tracker features a 15° × 15° field of view, with attitude determination accuracy greater than 5″ and roll accuracy better than 50″, while three star trackers—STR1, STR2, and STR3—provide the attitude quaternions of their coordinate systems relative to the inertial coordinate system at each sampling time. The quaternion data start from 12:00 on January 1, 2009, with a sampling frequency of 2 Hz, covering approximately two orbital periods.

该卫星搭载的星敏感器（star tracker）视场为15°×15°，姿态确定精度大于5角秒，滚转精度优于50角秒；三台星敏感器（STR1、STR2、STR3）可在每个采样时刻输出各自坐标系相对于惯性坐标系（inertial coordinate system）的姿态四元数。该四元数数据集起始于2009年1月1日12:00，采样频率为2赫兹（Hz），覆盖时长约为两个轨道周期。