大功率正交源张量CSAMT观测数据（2019）

大功率正交源张量CSAMT利用两个分离或重叠场源，测量两个场源的10个场分量（Ex1、Ex2、Ey1、Ey2、Hx1、Hx2、Hy1、Hy2、Hz1、Hz2），适于探测地下地质复杂或各向异性地质体。其有效测量范围为8个25°扇形范围。所以，相比常规CSAMT，大功率正交源张量CSAMT可以求解四个甚至六个到十个方向的张量阻抗要素，更适合在复杂地质条件下获得精确的二维，三维电性结构特征。仪器：发射机为SuperTX-150型150kw发射系统，接收机采用加拿大凤凰地球物理公司V8多功能电法工作站，发射频率0.375-1920Hz。场源：采用互相垂直的“十字”重叠场源，发射极AB极距3km；发射极海拔3800-3900m，最大高差131m；测线海拔4600-5300m；发射车与四个发射极之间的电极线长度大致相同（图7）。接收端：采用张量观测方式，即测量Ex、Ey、Hx、Hy、Hz五个分量；接收机采用“一拖二”（即一个V8盒子控制两个3ER）的方式。主要工作参数：发射极AB极距为3km；AB极电阻分别为13Ω和16Ω；收发距23～27km；发射电流60～65A；MN极距25-50m；观测时间1h。

High-power orthogonal-source tensor CSAMT utilizes two separate or overlapping field sources, and measures 10 field components from the two sources: Ex1, Ex2, Ey1, Ey2, Hx1, Hx2, Hy1, Hy2, Hz1, Hz2. It is suitable for detecting subsurface complex geological or anisotropic geobodies, with an effective measurement coverage of eight 25° sectors. Therefore, compared with conventional CSAMT, high-power orthogonal-source tensor CSAMT can solve tensor impedance elements in 4, even 6 to 10 directions, making it more suitable for obtaining accurate 2D and 3D electrical structural characteristics under complex geological conditions.

Instruments: The transmitter is the SuperTX-150 150 kW emission system; the receiver adopts the V8 multi-function electrical method workstation from Phoenix Geophysics of Canada, with an emission frequency range of 0.375–1920 Hz.

Field sources: A mutually perpendicular "cross-shaped" overlapping field source is adopted, with the AB electrode spacing of the transmitters being 3 km; the elevation of the transmitters ranges from 3800 to 3900 m, with a maximum elevation difference of 131 m; the elevation of the survey lines ranges from 4600 to 5300 m; the lengths of the electrode cables between the emission vehicle and the four transmitters are roughly the same (Figure 7).

Receiving end: Tensor observation mode is adopted, i.e., five components (Ex, Ey, Hx, Hy, Hz) are measured; the receiver uses the "one-to-two" configuration (i.e., one V8 unit controls two 3ERs).

Main operating parameters: The AB electrode spacing of transmitters is 3 km; the resistances of the AB electrodes are 13 Ω and 16 Ω respectively; the transmitter-receiver distance ranges from 23 to 27 km; the emission current is 60–65 A; the MN electrode spacing is 25–50 m; the observation duration is 1 hour.