基于SATC-CABP成像模型的天线姿态误差补偿方法

Compensation method of antenna attitude errors based on the SATC-CABP imaging model

分裂孔径发射配置(SATC)天线体制可取得与传统单站SAR相当的方位分辨率,且更适用于前视探测的运动平台。步进频率信号对相位极为敏感,平台的运动误差将导致天线阵的姿态发生变化,使得成像结果出现几何畸变。针对天线阵姿态误差对成像的影响,提出了一种基于分裂孔径发射配置下固定孔径后向投影(SATC-CABP)成像模型的补偿方法,通过传感器获取的姿态倾角修正成像模型中的参数,可在成像过程中实现天线姿态误差补偿。仿真结果表明,所提出的方法可得到聚焦良好的成像结果,且可很好地校正由天线阵姿态误差引起的目标成像位置畸变。

The split aperture transmit configuration （SATC） antenna system has a similar azimuth resolution to the conventional monostatic SAR, and it is more applicable to the forward-looking motorial platforms for exploration. Antenna attitude errors caused by the movement errors of the platforms, however, will lead to imaging distortion of the system with step frequency signal, which is very sensitive to the phase errors. To overcome the effects of the antenna attitude errors on the imaging results, a new compensation technique based on the constant aperture back-projection （CABP） imaging model under the SATC antenna system is presented. The novel method can compensate the attitude errors of the antenna array during the imaging process via modifying some parameters of the imaging model by using the pose obliquity obtained through sensitive sensors. The simulation results show that the proposed method can obtain good focused image and perfectly calibrate the distortion of targets imaging locations caused by the attitude errors of the antenna array.