Hayes R R
Appl Opt. 1997 Oct 20;36(30):8063-8. doi: 10.1364/ao.36.008063.
The narrow beam widths associated with intersatellite optical communication links make such links susceptible to signal fading because of pointing jitter. Such fading can be aggravated by stationary offsets in pointing. We calculated the fade rates for the case of two spaceborne telescopes having Gaussian beam profiles, a pointing offset, and pointing jitter that can be described by Gaussian statistics. An integral solution is derived for the general case of a nonsymmetrical system, with and without pointing bias, and closed-form solutions are presented for the case of a symmetrical system (identical platforms and optics). These results show that, for a system with 3-dB margin, the rms pointing jitter must be held to less than 7% of the full beam width to keep the fade rate below once per year.
星间光通信链路的窄波束宽度使得此类链路由于指向抖动而容易受到信号衰落的影响。指向中的固定偏移会加剧这种衰落。我们针对两台具有高斯光束轮廓、存在指向偏移以及可用高斯统计描述的指向抖动的星载望远镜的情况计算了衰落率。针对非对称系统（有无指向偏差）的一般情况推导了一个积分解，并给出了对称系统（相同平台和光学器件）情况下的闭式解。这些结果表明，对于具有3分贝裕度的系统，均方根指向抖动必须保持在全波束宽度的7%以下，以使衰落率保持在每年一次以下。
