(1. 中國科學(xué)院 電磁輻射與探測(cè)技術(shù)重點(diǎn)實(shí)驗(yàn)室，北京 100190；
2. 中國科學(xué)院大學(xué)，北京 100049；
3. 中國科學(xué)院 電子學(xué)研究所，北京 100190)
摘 要: 基于磁偶極子的航空頻率域電磁法儀器在飛行探測(cè)的過程中，由于吊艙姿態(tài)角的變化，使得收發(fā)線圈與大地之間的耦合發(fā)生變化，從而產(chǎn)生姿態(tài)誤差。根據(jù)誤差來源的不同，可以將姿態(tài)誤差分為方向誤差與位置誤差兩種。為了消除姿態(tài)誤差的影響，基于層狀大地模型，首先推導(dǎo)得到三軸發(fā)射、三軸接收線圈架構(gòu)下的電磁張量姿態(tài)旋轉(zhuǎn)不變量，再基于重疊偶極子模型，推導(dǎo)得到吊艙翻滾角及俯仰角的余弦值，進(jìn)而實(shí)現(xiàn)不變量位置誤差的校正。與傳統(tǒng)的姿態(tài)校正算法相比，不變量的姿態(tài)誤差校正算法無需測(cè)量吊艙的姿態(tài)角信息。由仿真結(jié)果可知，不變量的姿態(tài)校正算法可以實(shí)現(xiàn)傳統(tǒng)姿態(tài)校正算法在3種常用線圈架構(gòu)中的校正效果；在常見的H型與K型三層大地模型下，校正后不變量的相對(duì)誤差小于0.1%，從而驗(yàn)證了不變量姿態(tài)校正算法的可行性。
關(guān)鍵字: 航空頻率域電磁法；姿態(tài)誤差；電磁張量；姿態(tài)旋轉(zhuǎn)不變量；重疊偶極子模型
（1. Key Laboratory of Electromagnetic Radiation and Sensing Technology, Chinese Academy of Sciences, Beijing 100190, China;
2. University of Chinese Academy of Sciences, Beijing 100049, China;
3. Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China）
Abstract:There exist attitude errors resulting from the change of coupling between the coils and the earth for attitude angle change in the course of flight measurement of airborne frequency domain electromagnetic instruments. According to differences of sources, the attitude errors can be divided into the direction errors and the position errors. In order to eliminate the effect of attitude errors, this study firstly derives the electromagnetic tensor attitude rotational invariant from the coil configuration of tri-axial transmitter and tri-axis receiver in layered earth model. Then the cosines of roll angle and pitch angle can be deduced on the basis of superposed dipole model, achieving the correction of position errors of invariant. Compared with the traditional attitude correction algorithm, the attitude correction algorithm of invariant does not need to measure any attitude information. From the simulation results, the attitude correction algorithm of invariant can achieve the similar effects of traditional attitude correction algorithm in three common coil configurations. In the common H-type and K-type three-layer earth model, the relative error of invariant after correction is less than 0.1%, which proves the feasibility of the attitude correction algorithm of invariant.
Key words: airborne frequency domain electromagnetic method; attitude error; electromagnetic tensor; attitude rotational invariant; superposed dipole model
