摘要
深入分析了现行地面瞬变电磁法中存在关断电流斜坡响应的计算方法,指出其中存在的不合理之处,提出用冲激响应积分算法计算存在关断电流斜坡时的瞬变电磁响应,并应用于航空瞬变电磁法一维正演计算中.计算结果表明,当存在关断电流斜坡时,早期的感应电动势明显大于没有断电后沿的值,且受影响的时间范围约为十倍的电流后沿宽度;当后沿宽度较大时,甚至晚期的感应电动势也出现了明显的误差.由此得出,在航空瞬变电磁法仪器设计和实测资料处理过程中,关断电流斜坡的响应不容忽视.
After thorough studying the methods of calculating the ramp function turn-off effect presently on the ground TEM, we point out the defects existed. In this paper a more reasonable method impulse response integration algorithm is presented and applied for ATEM 1-D forward. The result show that, in the early period the amplitudes of the induced electromotive force with the ramp function effect are obviously higher than those without the effect, and the influenced time is about 10 times the ramp current lasted. If the ramp current last long, obvious error could be generated even in the late period amplitudes. Thus, the effect of the ramp function turn-off is unignorable in the field of ATEM instrument designing and data processing.
出处
《地球物理学进展》
CSCD
北大核心
2012年第1期105-111,共7页
Progress in Geophysics
基金
国家自然科学基金项目(41174104
40974076)资助
国家高科技发展计划项目(863-2006AA06A205-5-4
2007AA06Z134)资助
深部探测技术与实验研究专项(Sinoprobe-03-02-04)资助
关键词
航空瞬变电磁
关断电流斜坡响应
冲激响应积分算法
airborne electromagnetic method, response of ramp function turn-off, impulse response integration algorithm
