摘要
导航卫星在轨时星上接收机的两个重要考核指标是干扰下的测距精度与接收灵敏度。卫星受干扰时需提高地面主控站出站信号功率输出,会把地面高功率放大器推至饱和非线性工作区,从而引起非恒包络信号失真,继而导致星上接收机测距精度恶化,对上述现象进行分析,并提出了一种衡量星上测距精度的方法,分析表明上述方法能准确衡量在轨测试时星上的测距精度。同时,卫星在轨运行时星上接收天线只有主瓣对准地球,其余旁瓣对准冷空,导致天线温度与地面测试不同,引起星上接收机灵敏度变化。经过对上述现象进行分析,通过合理设计卫星接收天线方向图来减小灵敏度变化的程度。
Ranging accuracy under jamming and receiver sensitivity are key performance indicators in in - orbit operation for navigation satellite. The signal from ground control station will be enhanced when jamming occurs, which leads high power amplifier to non - linear workspace. Then non - constant envelope signal distortion increases and ranging accuracy decreases. This phenomenon is researched and a novel method to weigh ranging accuracy is proposed. Analysis result indicates that this method can measure ranging accuracy effectively. Also, because of re- ceiver antenna only main lobe points to the earth, the antenna temperature will be different from On - ground testing, which causes receiver sensitivity decrease. To avoid receiver sensitivity deteriorates seriously, antenna pattern should be designed reasonably.
出处
《计算机仿真》
CSCD
北大核心
2015年第8期37-40,共4页
Computer Simulation
