大气湍流对深空天线组阵相位影响分析

深空测控网采用大规模天线组阵系统比单个大天线具有一定优势,构建一个Ka频段的天线组阵系统无论对于星际测控通信还是天文观测都是一种经济、可持续扩展的技术方案。然而天线组阵系统工作于Ka频段时,由于天线间相位的快速起伏漂移将使得合成信噪比迅速恶化,尤其对于深空测控上行链路信号的相位监测和闭环控制带来巨大挑战,所以对天线间大气相位扰动测量和数值模拟非常必要。参考国外相关的干涉测量数据,首先分析了天线组阵大气相位扰动测量和统计分析方法;然后利用微波大气湍流模型,建立了天线组阵相位漂移抖动模型;对大气湍流引起的相位延迟扰动过程进行了仿真实现。利用模型产生的天线组阵相位抖动数值,可以测试和评估天线组阵信号合成处理系统的适用性。

Analysis of the Effect of Atmosphere Turbulence on Antenna Arraying Phase Fluctuations

Large scale antenna arraying system is superior than a single large antenna in deep space TT&C network. Building a Ka band antenna array system is a cost-effective and sustainable technical scheme for interplanetary TT&C and astronomical observation. However, due to the rapid fluctuation of the phase drift between antennas, the synthetic signal to noise ratio (SNR) will be deteriorated rapidly when the antenna array working at Ka band. The phase drift also brings challenges for deep space uplink signals phase monitoring and closed-loop control, so it is necessary to measure and numerically simulate the atmospheric phase disturbance between the antennas. Based on the relevant interferometry data, the atmospheric phase disturbance measurement method and statistical analysis method of the antenna array are analyzed, and then the antenna array phase drift jitter model is established by using the microwave atmospheric turbulence model. Several phase delay disturbance processes caused by atmospheric turbulence are simulated based on the model. Using the above model, the applicability of the antenna array signal synthesis processing can be tested and evaluated.