时间域航空电磁系统姿态变化影响研究

Influence of attitude change for time domain airborne electromagnetic system

航空电磁系统的收发线圈受外界因素影响会发生姿态变化,使测量结果产生一定偏差.传统的数据处理方法考虑姿态变化情况单一,且主要以频率域系统为主,而目前复杂姿态变化对时间域航空电磁系统全时响应的影响尚未有系统研究.本文在前人研究基础上拓宽思路,不仅研究姿态的角度变化,同时改进前人计算方法,研究线圈发生位置变化的影响,并将线圈与大地的耦合感应效应考虑在内.本文通过定义姿态变化前后两种坐标系,确定姿态变化的角度和旋转矩阵,并将一维层状半解析解与姿态角度变化和位置变化进行整合,推导出收发线圈任意姿态变化的表达式.以直升机吊舱分离装置为例,对时间域航空电磁系统收发线圈任意姿态变化进行细致分析.基于重叠偶极子的假设,给出可应用于实际工作中的姿态校正因子,以提高实测数据的处理效率与精度.

The attitude of the receiver and transmitter coil of the airborne electromagnetic（AEM）system will be influenced by many external factors,which lead to a certain deviation of the measurement results.In previous studies,the processing methods of AEM data mainly consider the attitude change in frequency-domain.However,few of them focus on the complex situation of attitude change for time-domain AEM system.In this paper,we not only carry on a series of researches on angle change of attitude,but also improve the existing algorithm and take the coupling effect of coils and earth into account to study the influence of position change of coils by defining the two coordinate systems of attitude,we determine angle and rotation matrix ofattitude change.Integrating the 1 Dlayered semi-analytical solution with the change of angle and location,we derive the equation of attitude change of transform and receive coil.Additional,we taking the towed-bird separation system of helicopter as an example to analysis the arbitrary attitude change of the transceiver coil of time-domain AEM system.Moreover,based on the assumption of superposed dipole model,we provide the attitude correction factors which can be applied in practical work and improve the efficiency and precision of the measured data processing.