Conlon Lorcán O, Michel Thibault, Guccione Giovanni, McKenzie Kirk, Assad Syed M, Lam Ping Koy
Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Australian National University, Canberra, ACT, 2601, Australia.
Centre for Gravitational Astrophysics (CGA), Research School of Physics, The Australian National University, Canberra, ACT, 2601, Australia.
NPJ Microgravity. 2022 Jun 8;8(1):21. doi: 10.1038/s41526-022-00204-9.
Satellite geodesy uses the measurement of the motion of one or more satellites to infer precise information about the Earth's gravitational field. In this work, we consider the achievable precision limits on such measurements by examining approximate models for the three main noise sources in the measurement process of the current Gravitational Recovery and Climate Experiment (GRACE) Follow-On mission: laser phase noise, accelerometer noise and quantum noise. We show that, through time-delay interferometry, it is possible to remove the laser phase noise from the measurement, allowing for almost three orders of magnitude improvement in the signal-to-noise ratio. Several differential mass satellite formations are presented which can further enhance the signal-to-noise ratio through the removal of accelerometer noise. Finally, techniques from quantum optics have been studied, and found to have great promise for reducing quantum noise in other alternative mission configurations. We model the spectral noise performance using an intuitive 1D model and verify that our proposals have the potential to greatly enhance the performance of near-future satellite geodesy missions.
卫星大地测量学利用对一颗或多颗卫星运动的测量来推断有关地球引力场的精确信息。在这项工作中，我们通过研究当前重力恢复与气候实验后续任务（GRACE Follow-On）测量过程中三个主要噪声源的近似模型，来考虑此类测量可达到的精度极限：激光相位噪声、加速度计噪声和量子噪声。我们表明，通过时延干涉测量法，可以从测量中去除激光相位噪声，从而使信噪比提高近三个数量级。文中提出了几种差分质量卫星编队，通过去除加速度计噪声可进一步提高信噪比。最后，对量子光学技术进行了研究，发现其在降低其他替代任务配置中的量子噪声方面具有很大潜力。我们使用直观的一维模型对频谱噪声性能进行建模，并验证我们的提议有潜力极大地提高近期卫星大地测量任务的性能。
