We quantify the calibration requirements for systematic uncertainties for next-generation ground-based observatories targeting the large-angle B-mode polarization of the Cosmic Microwave Background, with a focus on the Simons Observatory (SO). We explore uncertainties on gain calibration, bandpass center frequencies, and polarization angles, including the frequency variation of the latter across the bandpass. We find that gain calibration and bandpass center frequencies must be known to percent levels or less to avoid biases on the tensor-to-scalar ratio r on the order of Δ r∼10^-3, in line with previous findings. Polarization angles must be calibrated to the level of a few tenths of a degree, while their frequency variation between the edges of the band must be known to O(10) degrees. Given the tightness of these calibration requirements, we explore the level to which residual uncertainties on these systematics would affect the final constraints on r if included in the data model and marginalized over. We find that the additional parameter freedom does not degrade the final constraints on r significantly, broadening the error bar by O(10%) at most. We validate these results by reanalyzing the latest publicly available data from the collaboration within an extended parameter space covering both cosmological, foreground and systematic parameters. Finally, our results are discussed in light of the instrument design and calibration studies carried out within SO.

我们量化了针对宇宙微波背景的大角度 B 模式极化的下一代地面观测站的系统不确定性的校准要求，重点是西蒙斯天文台 (SO)。我们探讨了增益校准、带通中心频率和极化角的不确定性，包括后者在带通上的频率变化。我们发现增益校准和带通中心频率必须知道百分比水平或更少，以避免在 Δr∼10 ^{-3量级上的张量与标量比 r 的偏差}，与之前的研究结果一致。偏振角必须校准到十分之几度的水平，而它们在频带边缘之间的频率变化必须知道 O(10) 度。鉴于这些校准要求的严格性，我们探讨了这些系统的剩余不确定性如果包含在数据模型中并被边缘化，将影响对 r 的最终约束的程度。我们发现额外的参数自由度不会显着降低对 r 的最终约束，最多将误差条扩大 O(10%)。我们通过在涵盖宇宙学、前景和系统参数的扩展参数空间内重新分析来自合作的最新公开可用数据来验证这些结果。最后，