Ground - based instruments such as the giant keck telescopes have amassed statistics on distant ( and therefore ancient ) galaxies 地面望远镜,如巨大的凯克望远镜,已经累积了远处(所以是古老的)星系的大量统计资料。
Ligo and the other ground - based detectors are sensitive to frequencies from a few tens of hertz ( cycles per second ) to a few thousand hertz Ligo和其它的地基探测器对从几十赫兹(每秒的周期数)到几千赫兹的频率都是敏感的。
Over the years , considerable progress has been made in the development of detection systems , both ground - based and on - board aircraft 经过科学家多年来的研究,监测微下击暴流的系统性能大为提高,更可以在地面或飞机上进行监测。
Since we made this prediction , hubble and ground - based telescopes have analyzed the colors of the globular clusters in elliptical galaxies 由于我们做出了这样的预测,哈伯望远镜及其他地面望远镜因而分析了球状星团在椭圆星系里的颜色。
Transport captain we ' re on a top secret mission and i ' m not transmitting a valid friendly id signal to the ground - based automatic defense systems 我们正在执行一次绝密的任务,而且我们不能发送有效的友军识别信号给地面的自动防空系统。