用无线电应答机相控阵精确跟踪小行星轨道
Precise Orbital Tracking of an Asteroid with a Phased Array of Radio Transponders
摘要：
使小行星偏离地球撞击轨道只需要很小的速度变化，如果提前很多年完成，通常是每秒微米的数量级。为此，需要一种高度精确的方法来确定偏转的需要、大小和方向。虽然所需的精度可以通过精度低得多的扩展观测来实现，但$μ$ m/s的固有分辨率允许实时监测非引力轨道摄动（雅科夫斯基效应）和偏转作用本身。这里，建议在小行星表面部署多个无线电装置，形成一个相控阵列，能够测量相对于地球的径向速度，约为1 $μ$ m/s，范围为5 m。同样的技术也可用于科学应用，如甚长基线射电天文学、毫赫兹引力波探测或太阳风测绘。
英文摘要：
Deflecting an asteroid from an Earth impact trajectory requires only small velocity changes, typically of the order of microns per second, if done many years ahead of time. For this, a highly precise method of determining the need, magnitude, and direction of a deflection is required. Although the required precision can be achieved by much less accurate extended observations, an intrinsic resolution of $μ$m/s permits the live monitoring of nongravitational orbital perturbations (Yarkovsky effect), and of a deflection effort itself. Here, it is proposed to deploy on the asteroid's surface multiple radio units to form a phased array capable of measuring radial velocities relative to Earth to about 1 $μ$m/s and ranges to 5 m. The same technology can also be used for scientific applications such as very-long baseline radio astronomy, milli-Hertz gravitational wave detection, or mapping of the solar wind.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
