论文部分内容阅读
一、引言在卫星通信系统中,为使地面站天线能够自动跟踪卫星,通常采用自动跟踪方法和程序控制方法。自动跟踪方法的实现可采用射束控制方式、多喇叭跟踪方式、步进跟踪方式以及多模跟踪方式等。用射束控制方式时,天线波束的旋转将引起通信信号波调幅以及当两个以上的地面站使用这种方式时有可能产生较大的跟踪误差,所以这种方式目前已很少使用。多喇叭跟踪方式曾用在福齐诺地面站和詹姆斯堡地面站。但是,结构很复杂且影响天线增益的提高,故已很少使用。步进跟踪方式是以大约0.01度的固定步进增大或减少天线的指向角,如果一次步进后接收到的信号较前增大,则继续在此方向上步进;而如果一次步进后
I. INTRODUCTION In the satellite communication system, automatic tracking methods and program control methods are usually used to enable the ground station antenna to automatically track the satellite. Automatic tracking method can be achieved using beam control, multi-horn tracking, step-by-step tracking and multi-mode tracking. In beam control mode, the rotation of the antenna beam causes the amplitude of the communications signal to be amplitude modulated, and the greater tracking error may occur when using more than two ground stations in this manner, so this method is seldom used today. Multi-horn tracking has been used at the Fusino ground station and the James Fort ground station. However, the structure is very complicated and affects the improvement of the antenna gain, it is seldom used. The step-by-step tracking mode is to increase or decrease the pointing angle of the antenna with a fixed step of about 0.01 degree. If the received signal is larger than the previous one after the step, the stepper continues to be stepped in. If the stepper Rear