在恒星掩星和人造地球卫星跟踪中达到亚毫秒精度
Reaching sub-millisecond accuracy in stellar occultations and artificial satellites tracking
摘要：
近年来，出现了需要天文观测时间与亚毫秒的精度。例如，这些包括由小型、亚公里或快速近地小行星对恒星掩星进行计时，但也包括使用光学传感器跟踪低地球轨道上的人造地球卫星。快速移动卫星的精确天体测量和恒星掩星的精确定时有着并行的需求，需要可靠的时间源和对相机延迟的良好了解。因此，需要一种外部设备，使设备和相机测试，以检查它们是否达到所需的精度。我们设计、构建并彻底测试了一个新的EXTA定时分析器（NEXTA）：一个基于GNSS的精确定时器（全球导航卫星系统），可以达到0.1毫秒的精度，比以前可用的工具好一个数量级。该设备是一个简单的闪烁二极管带，与被测相机成像，并将成像时间与内部相机时间戳进行比较。我们的测试涵盖了广泛用于恒星掩星和地面卫星跟踪的一系列科学相机。结果显示NEXTA和大多数测试相机的可靠性都很高，但也指出几乎所有相机都有不同程度的内部时间偏差。NEXTA可以为社区服务，可以用廉价的组件轻松复制。我们提供所有必要的方案和使用说明。
英文摘要：
In recent years there appeared a need for astronomical observations timed with sub-millisecond accuracy. These include e.g. timing stellar occultations by small, sub-km or fast Near Earth Asteroids, but also tracking artificial satellites at Low Earth Orbit using optical sensors. Precise astrometry of fast-moving satellites, and accurate timing of stellar occultations have parallel needs, requiring reliable time source and good knowledge of camera delays. Thus a need for an external device that would enable equipment and camera testing, to check if they reach the required accuracy in time. We designed, constructed and thoroughly tested a New EXposure Timing Analyser (NEXTA): a GNSS-based precise timer (Global Navigation Satellite System), allowing to reach the accuracy of 0.1 millisecond, which is an order of magnitude better than in previously available tools. The device is a simple strip of blinking diodes, to be imaged with a camera under test and compare imaged time with internal camera time stamp. Our tests spanned a range of scientific cameras widely used for stellar occultations and ground-based satellite tracking. The results revealed high reliability of both NEXTA and most of the tested cameras, but also pointed that practically all cameras had internal time bias of various level. NEXTA can serve the community, being easily reproducible with inexpensive components. We provide all the necessary schemes and usage instructions.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
