近区瞬变电磁测深曲线畸变段的消除方法

ELIMINATE METHOD FOR DISTORTED STAGE OF TRANSIENT ELECTROMAGNETIC SOUNDING CURVE IN NEAR-ZONE

讨论了利用P.Raab和F.Frischknecht给出的中心回线装置瞬变衰减电压表达式,采用编程求解的方法来计算适用于全时域的视电阻率ρ_r。这种视电阻率曲线克服了以往使用晚期计算视电阻率公式所得到的曲线,对于任何模型的左支曲线都将产生畸变的缺点,它的早期渐近线为趋于第一层电阻率值的水平直线。

The article will discuss about the method of using P. Raab and F. Frischknechts expression of the transient decay voltage for a central loop system, abopting the methodology of making program to counl the all-time apparent resistivity ρ_τ. The apparent resistivity curve have overcomed the disadvantage of distorted at the left of curves, which occurred by used the latetime apparent resistivity formula for any models.