Large angular scale surveys in the absence of atmosphere are essential for measuring the primordial B-mode power spectrum of the Cosmic Microwave Background (CMB). Since this proposed measurement is about three to four orders of magnitude fainter than the temperature anisotropies of the CMB, in-flight calibration of the instruments and active suppression of systematic effects are crucial. We investigate the effect of changing the parameters of the scanning strategy on the in-flight calibration effectiveness, the suppression of the systematic effects themselves, and the ability to distinguish systematic effects by null-tests. Next-generation missions such as LiteBIRD, modulated by a Half-Wave Plate (HWP), will be able to observe polarisation using a single detector, eliminating the need to combine several detectors to measure polarisation, as done in many previous experiments and hence avoiding the consequent systematic effects. While the HWP is expected to suppress many systematic effects, some of them will remain. We use an analytical approach to comprehensively address the mitigation of these systematic effects and identify the characteristics of scanning strategies that are the most effective for implementing a variety of calibration strategies in the multi-dimensional space of common spacecraft scan parameters. We verify that LiteBIRD's standard configuration yields good performance on the metrics we studied. We also present Falcons.jl, a fast spacecraft scanning simulator that we developed to investigate this scanning parameter space.

中文翻译：

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对 LiteBIRD 太空任务的扫描策略进行多维优化


在没有大气层的情况下进行大角度尺度的巡天对于测量宇宙微波背景 （CMB） 的原始 B 模式功率谱至关重要。由于这种拟议的测量比 CMB 的温度各向异性微弱约 3 到 4 个数量级，因此仪器的飞行校准和系统效应的主动抑制至关重要。我们研究了更改扫描策略参数对飞行校准效果、系统效应本身的抑制以及通过零检验区分系统效应的能力的影响。由半波板 （HWP） 调制的 LiteBIRD 等下一代任务将能够使用单个探测器观察极化，无需像以前的许多实验那样组合多个探测器来测量极化，从而避免了随之而来的系统效应。虽然预计 HWP 将抑制许多系统性影响，但其中一些影响仍然存在。我们使用分析方法来全面解决这些系统效应的缓解问题，并确定扫描策略的特征，这些策略对于在常见航天器扫描参数的多维空间中实施各种校准策略最有效。我们验证了 LiteBIRD 的标准配置在我们研究的指标上产生了良好的性能。我们还介绍了 Falcons.jl，这是我们开发的一个快速航天器扫描模拟器，用于研究这个扫描参数空间。