Schartner Matthias, Böhm Johannes
Department of Geodesy and Geoinformation, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria.
J Geod. 2020;94(1):12. doi: 10.1007/s00190-019-01340-z. Epub 2020 Jan 8.
Very long baseline interferometry (VLBI) scheduling is a challenging optimization problem. With the development of the new VLBI global observing system (VGOS) consisting of smaller but very fast slewing antennas, new opportunities arise. In this work, we give a deep insight into optimized VGOS scheduling using a newly developed VLBI scheduling software called VieSched++, and we show how different scheduling parameters and approaches affect the precision of geodetic results. Therefore, the results of over one thousand generated schedules and over one million simulated sessions are analyzed. The simulations reveal that the most important parameters to optimize VGOS schedules with VieSched++ are the so-called weight factors. A proper selection of individually optimized weight factors can improve the quality of a schedule significantly. It is shown that the values of the weight factors used to generate the schedule are highly correlated with the expected precision of the geodetic parameters. We highlight the benefit of selecting schedules based on large-scale Monte Carlo simulations and show why scheduling statistics like the number of observations or the sky-coverage are not necessarily the best metric to evaluate schedules.
甚长基线干涉测量（VLBI）调度是一个具有挑战性的优化问题。随着由更小但转速极快的天线组成的新型VLBI全球观测系统（VGOS）的发展，新的机遇应运而生。在这项工作中，我们使用一种新开发的名为VieSched++的VLBI调度软件，深入洞察优化后的VGOS调度，并展示不同的调度参数和方法如何影响大地测量结果的精度。因此，我们分析了一千多个生成的调度结果和一百多万个模拟会话的结果。模拟结果表明，使用VieSched++优化VGOS调度的最重要参数是所谓的权重因子。正确选择单独优化的权重因子可以显著提高调度质量。结果表明，用于生成调度的权重因子值与大地测量参数的预期精度高度相关。我们强调基于大规模蒙特卡罗模拟选择调度的好处，并说明为什么像观测次数或天空覆盖范围这样的调度统计数据不一定是评估调度的最佳指标。
