全天中性氢吸收光谱测量（MANAS）
Measurement of All-sky Neutral hydrogen Absorption Spectrum (MANAS)
AI总结：
研究旨在测量宇宙黎明的天空平均红移21厘米信号，核心方法是结合多种设备并制定误差预算，主要贡献是能量化如天空、电离层等系统误差对21厘米实验的影响。
AI中文摘要：
MANAS是一个单天线地面平台，用于测量来自宇宙黎明的天空平均（“全局”）红移21厘米信号。宇宙学信号预计是一个约100 - 200 mK的吸收谷，背景比其亮3 - 4个数量级。当前的21厘米实验受系统误差限制，如天空、电离层、波束和信号路径效应。MANAS结合消色差单极天线、绝对校准接收器等，并制定端到端误差预算来量化各系统误差。
英文摘要：
MANAS is a single antenna, ground-based platform built to measure the sky averaged ('global') redshifted 21-cm signal from Cosmic Dawn. The cosmological signal is expected as a ~ 100-200 mK absorption trough against a foreground of 3-4 orders of magnitude brighter. The current crop of 21-cm experiments are limited by systematics namely the sky, ionosphere, beam, and signal path effects. MANAS combines an achromatic monopole antenna, an absolutely-calibrated receiver, and in-situ beam mapping with the OVRO-LWA, and develops an end-to-end error budget that quantifies each systematic.
