基于变步长算法的航天测控雷达多站跟踪技术研究

Research on Multi-station Tracking Technology of TT&C Radar Based on Variable Step Size Algorithm

径向速度作为现代雷达测量目标特征的重要参量,提高对其的精确测量能力是目前航天测控领域重要的研究方向之一;实际上一台单脉冲雷达通常综合测距、速、角等功能,选取的重复频率不足以使雷达测速无模糊,因此必须进行解速度模糊操作;基于不变量嵌入法的解速度模糊技术更加成熟,但解模糊的时间相对较长;变重复频率法能够有效的解速度模糊以获取精确值,但通过实验证明其进行的变频率操作与航天发射领域普遍运用的多站工作模式要求不相符,容易造成信号阻塞导致解速度模糊失败;在传统谱峰搜索方法基础上,改进的变步长谱峰搜索方法通过区域搜索,改变检索步长的方式,在单站工作模式下检索7次获取谱峰所在区域,并利用频谱偶对称性质有效减少系统噪声的影响,极大地提升了解速度模糊效率和精度,在多站工作的模式下,变步长搜索算法比传统搜索算法更具优势。

Radial velocity is an important parameter for modern radar to measure target characteristics,and improving its accurate measurement capability is one of the important research directions in the field of aerospace measurement and control.In fact,a mono-pulse radar usually is integrated with the functions of distance,speed,angle measurement.The selected repetition frequency is not enough to make the radar speed measurement without the ambiguity,so the resolving velocity ambiguity must be performed.The resolving velocity ambiguity based on the invariant embedding method is more mature,but the ambiguity time is relatively long.The variable repetition frequency method can effectively solve the velocity ambiguity to obtain the accurate value,but it is proved by experiments that the variable frequency operation does not meet the requirements of the multi-station working mode commonly used in space launch sites,which easily causes signal blockage and lead to the failure of velocity ambiguity resolution.By the traditional spectral peak search method,the improved variable-step spectral peak search method changes the search step size through the regional search,searches seven times in the single-station working mode to obtain the region where the spectral peak is located,and the even symmetry property of the spectrum is used to effectively reduce the impact of system noise and greatly improve the speed of understanding,fuzzy efficiency and accuracy.The variable-step search algorithm has more advantages than the traditional search algorithm in the mode of multi-station operation.