太阳辐射对环火段通信链路的影响分析及参数设计

深空探测的上合阶段(superior solar conjunction,SSC)，太阳强辐射成为影响地面站接收噪声温度计算分析的关键性因素之一。针对太阳辐射引起的高传输误码率甚至通信中断问题，以火星探测为例，提出一种定量化计算环火段太阳 地面站 探测器夹角∠SEP的方法，结合角度关系分析了环火段SSC阶段太阳对链路产生影响的原因，重点分析了地面站接收太阳噪声温度与空间链路、空口参数以及天线波束特性之间的关系。研究及仿真试验表明，当天线口径一定时，地面站的接收噪温峰值Tsmax和太阳对地面站的影响时长ti均与通信频率成反比; 在通信频率一定时，Tsmax与天线口径成正比，t_i与天线口径成反比；当天线口径固定为34m时，S频段下的Tsmax高达12830K，是Ka频段下的1.8倍，S频段的ti比Ka频段下的ti表现在∠SEP上延长近0.5°。当通信频率固定为S频段时，70m口径天线与18m口径天线相比，Tsmax高出1920K，但是ti表现在∠SEP上缩短约0.53°。结合太阳辐射对通信链路的影响分析，给出了不同∠SEP下的链路参数设计建议，为火星探测链路中的参数设置提供参考。

Analysis of influence of solar radiation on communication links during Mars orbiter operation and link parameter design

In the super solar junction (SSC) stage of deep space communications, strong solar radiation is one of the key factors that affect the calculation and analysis of the received noise temperature of the ground station. Aiming at the problem of high transmission error rate and communication interruption caused by solar radiation, taking Mars exploration as an example, a research method for calculating Sun-Earth-Probe angle ∠SEP during the operation of the orbiter was proposed. Combined with ∠SEP, the cause for the influence of the Sun on the link in the SSC stage was analyzed. The focus was on the relationship between the solar noise temperature received by the ground station and ∠SEP, air interface parameters, and antenna beam characteristics. Research and simulation experiments show that when the antenna diameter is constant, the peak value of the noise temperature received by the ground station and the influence time of the Sun on the ground station are inversely proportional to the communication frequency. And when the communication frequency is constant, the peak value of the noise temperature received by the ground station is proportional to the antenna diameter. But the influence time of the Sun on the ground station is inversely proportional to the antenna aperture. Combined with the analysis of the influence of solar radiation on the communication link, the link parameter design suggestions under different ∠SEP were given, which provided a reference for the parameter setting in the Mars exploration project.