机动平台俯冲大斜视SAR脉冲重复频率设计

在机动平台俯冲段大斜视合成孔径雷达(synthetic aperture radar, SAR)成像中,传统脉冲重复频率(pulse repetition frequency, PRF)设计方法存在下限值过高导致数据录取量增加,且PRF值无法根据高度变化实时调整的缺陷。针对上述问题,首先构建机动平台俯冲大斜视SAR成像模型;然后提出一种新的基于等距离环的方位带宽计算方法,得到考虑运动及系统误差情况下的PRF下限值;最后提出分高度段动态选取PRF的新方法,根据平台位置动态调整较少次数的PRF值即可实现波束覆盖区内回波数据录取,解决了PRF值无法随高度变化实时调整的难题。

Pulse repetition frequency design for diving highly squinted synthetic aperture radar mounted on maneuvering platform

In diving highly squinted synthetic aperture radar (SAR) imaging, the traditional sequence design method of pulse repetition frequency (PRF) has the disadvantage that the lower limit value is too high to increase the data acquisition, and the PRF value cannot be adjusted in real time with the altitude of platform changing. In order to solve the above problems, a diving high squint imaging model mounted on the maneuvering platform is constructed firstly. Furthermore, the azimuth bandwidth calculation method based on equal-range rings is proposed to get the lower limit of PRF which takes motion and system error into consideration. Finally, the method of dynamic selection of PRF by dividing altitude segments is proposed, which can be adjusted dynamically according to the platform position. A few adjusting times of PRF value can realize the echo data acquisition in the beam coverage area, which solves the problem that PRF value cannot be adjusted in real time with the change of the altitude.