[论文解读] Towards a realistic noise modelling of quantum sensors for future satellite gravity missions

J. Encarnação, Christian Siemes+5 more|arXiv (Cornell University)|Apr 11, 2024

Solar and Space Plasma Dynamics被引用 4

一句话总结

本文為未來衛星重力任務中的冷原子干涉儀（CAI）傳感器開發了現實的噪聲模型，分析了衛星姿態誤差對科里奧利加速度的影響。比較了並行與串行運作模式，結果顯示串行模式透過以零速度原子雲起始，顯著降低了姿態相關誤差，大幅提升了低頻重力梯度測量的準確度。

ABSTRACT

Mapping the Earth's gravity field from space offers valuable insights into climate change, hydro- and biosphere evolution, and seismic activity. Current satellite gravimetry missions have demonstrated the utility of gravity data in understanding global mass transport phenomena, climate dynamics, and geological processes. However, state-of-the-art measurement techniques face noise and long-term drift limitations, which propagate into the recovery of Earth's time-varying gravity field. Quantum sensors, particularly Cold Atom Interferometry (CAI), offer promise for improving the accuracy and stability of space-based gravity measurements. Therefore, CAI has emerged as a promising measurement technique for future gravimetric satellite missions due to their potential for measuring gravitational forces and gradients with high precision and accuracy, particularly at low frequencies (sub-mHz). This study explores the sensitivity of CAI accelerometers and gradiometers to the errors in measuring the satellite's attitude. We explore the low-low satellite-to-satellite and gravity gradiometry concepts and build the respective analytical models of measurements and associated errors. We selected an ambitious scenario for CAI parameters that illustrates a potential path for increasing instrument accuracies and capabilities for space gravimetry. Two operational modes, concurrent (where a new cloud is generated while another is moved to the interferometric chamber) and sequential (where cloud generation and interferometry happen in the same place), are compared to mitigate the effects of inaccurately known attitude rates on Coriolis accelerations. The sequential mode shows the potential to reduce these effects since the atom cloud has an initial zero velocity. [...]

研究动机与目标

• 評估衛星姿態誤差對空間重力任務中冷原子干涉儀（CAI）測量的影響。
• 建立因姿態速率知識不準確而產生的噪聲來源模型，特別是科里奧利加速度的影響。
• 比較CAI的並行與串行運作模式，以減輕姿態引起的誤差。
• 評估CAI在未來任務中實現高精度、低頻重力梯度測量的潛力。
• 為即將開展的地球觀測衛星任務提供現實儀器性能建模的基礎。

提出的方法

• 發展用於低低衛星間鏈路跟蹤與重力梯度測量的CAI傳感器之解析模型。
• 建立姿態速率不準確的誤差傳播模型，專注於科里奧利加速度對原子干涉儀的影響。
• 模擬兩種運作模式：並行模式（同時產生原子雲與進行干涉測量）與串行模式（在同一位置順序產生原子雲與進行干涉測量）。
• 量化初始原子雲速度對科里奧利誤差敏感度的影響，結果顯示零初始速度條件更具優勢。
• 使用高性能CAI參數情境，預測可達的噪聲水平與誤差抑制效果。
• 在現實任務限制下，評估加速度計與梯度計對姿態誤差的敏感度。

实验结果

研究问题

• RQ1 姿態速率知識不準確如何影響冷原子干涉儀中的科里奧利加速度？
• RQ2 並行與串行運作模式在抑制姿態引起的誤差方面，相對表現如何？
• RQ3 串行運作模式在何等程度上能透過實現零初始速度原子雲來減少科里奧利誤差？
• RQ4 使用現實的CAI建模，低頻重力梯度測量可實現多大程度的噪聲降低？
• RQ5 CAI傳感器參數如何影響未來衛星重力任務的可行性？

主要发现

• 串行運作模式透過以原子雲零初始速度起始，顯著降低了科里奧利加速度誤差。
• 由於對初始條件有更好的控制，串行模式比並行模式更有效地抑制姿態引起的噪聲。
• 現實噪聲建模顯示，姿態速率誤差是基於CAI的重力梯度計中低頻噪聲的主要來源。
• 本研究示範了在優化CAI參數下，亞毫赫茲重力梯度測量可達高精度。
• 解析模型為預測在現實任務條件下的儀器性能提供了框架，有助於未來任務設計。