A LASER GYROSCOPE SYSTEM TO DETECT THE GRAVITO-MAGNETIC EFFECT ON EARTH
A LASER GYROSCOPE SYSTEM TO DETECT THE GRAVITO-MAGNETIC EFFECT ON EARTH
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DOI：
10.1142/s0218271810018360
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发表时间：
2010-12-01
影响因子：
2.2
通讯作者：
Ortolan, A.
中科院分区：
文献类型：
--
作者：
Di Virgilio, A.;Schreiber, K. U.;Ortolan, A.
每边长4米的大型方环激光陀螺的灵敏度接近1 × 10 ~（-11）rad/s/root Hz。这大约是测量地球的重磁效应（Lense-Thirring）所需的状态。对于线性独立陀螺仪的集合，每个测量信号取决于每个单轴陀螺仪相对于地球旋转轴的取向。因此，至少需要三个陀螺仪来重建设备的完整角取向。一般来说，该装置由几个激光陀螺仪组成（为了足够的冗余，我们希望多于三个），彼此严格参考。为一个观察平面增加更多的陀螺仪提供了针对系统内偏差的交叉检查，并且还具有通过陀螺仪数量的平方根来提高信噪比的优点。在本文中，我们分析了一个系统的两对相同的陀螺仪（双胞胎）与略有不同的方向相对于地球的轴。双陀螺布局有几个有趣的特性。可以控制相对角度，并提供有用的零位测量。四重孪生系统在每个方环边长为6 m的情况下，在3.2年的数据采集后可以达到1%的灵敏度，该系统受到散粒噪声的限制，并且没有1/f噪声源。
Large scale square ring laser gyros with a length of four meters on each side are approaching a sensitivity of 1 x 10(-11) rad/s/root Hz. This is approximately the regime required to measure the gravito-magnetic effect (Lense-Thirring) of the Earth. For an ensemble of linearly independent gyros each measurement signal depends upon the orientation of each single axis gyro with respect to the rotational axis of the Earth. Therefore at least three gyros are necessary to reconstruct the complete angular orientation of the apparatus. In general, the setup consists of several laser gyroscopes (we would prefer more than three for sufficient redundancy), rigidly referenced to each other. Adding more gyros for one plane of observation provides a cross-check against intra-system biases and furthermore has the advantage of improving the signal-to-noise ratio by the square root of the number of gyros. In this paper we analyze a system of two pairs of identical gyros (twins) with a slightly different orientation with respect to the Earth's axis. The twin-gyro configuration has several interesting properties. The relative angle can be controlled and provides a useful null measurement. A quadruple twin system could reach a 1% sensitivity after 3.2 years of data taking, provided each square ring has 6m length on a side, the system is limited by shot noise and there is no source for 1/f-noise.