中文摘要：

航空瞬变电磁的发射电流波形常常不稳定，论文对固定翼航空瞬变电磁发射波形的变化对响应的影响做理论分析，为系统波形设计提供理论指导．论文通过模拟计算任意发射电流脉冲下的一维模型的水平和垂直分量的感生电动势响应，来定量分析梯形电流脉冲波形变化大小对瞬变响应的影响情况．计算结果表明，在发射脉冲峰值电流相同条件下，发射波形会对瞬变响应结果产生一定程度的影响，发射脉冲越接近矩形脉冲，溃入地下的电磁场能量就越大，响应幅度就相对较大．发射波形变化对早期响应的影响程度较大，对晚期响应的影响程度相对小，下降沿的时间长度改变对响应结果影响程度大于上升沿时宽变化的影响程度．在本文的理论系统参数下，使用100Ωm米的均匀半空间模型，计算结果显示，当上升沿和单脉冲总供电时间不变时，梯形脉冲下降沿时间长度变化的相对误差±5％时，可分别在断电后0．282ms和0．116ms以后测量的X和Z分量感生电动势响应变化的相对误差在5％以内；当要求观测的响应数据的相对误差不超过5％时，接收时间应当在0．155ms之后且发射脉冲后沿时宽的范围在2．109～1．898ms以内．

英文摘要：

The transmitter current waveform of the Airborne Transient Electromagnetic often unstable. This paper studies the effect of transmitter current waveform variation to the fixed-wing Airborne Transient Electromagnetic response, which provide theoretical guidance for the system waveform design. By simulating the horizontal and vertical components of the induced emf response of a layered medium with Arbitrary emission current pulse, we quantitative analysis how the trapezoidal current waveform variation influences the transient response. The results show that, under the same conditions of the transmit current（with the same pulse peak）, the transmitted waveform will affect the transient Electromagnetic response to a certain extent. The more the transmit pulse close to the rectangular pulse, the greater electromagnetic field energy collapse into the underground, and simultaneously the response amplitude is relatively large. The effect to the transient response because of the transmitter current waveform variation is more larger to early time than the late time, and the length of time change with the current waveform in falling edge is more larger than the rising edge. On the homogeneous half-space model （100 μm） ,when the width of the falling time of the trapezoidal pulse haves the relative error of ＋5%, the relative error of the x and z component response will less than 5% after 0. 282 ms and 0. 116 ms the power off; When response data has the relative error less than ±5% after0. 155 ms the power off, the variation range of the falling edge of the trapezoidal pulse must less than 2. 109~1. 898 ms.