Airborne electromagnetic non-rigid pod system

In a non-rigid pod system, Figure 4? 1? 1(d) Generally, the receiving coil is towed in the pod behind the aircraft, and the pod is connected with the aircraft through a towing cable at least 50m long. Its advantage is that it can overcome the noise influence when the receiving coil is close to the plane. However, because the receiving coil constantly changes its coupling with the primary field, the real part cannot be measured. Therefore, the system only measures the imaginary part. Obviously, it is a loss not to measure the true component.

We know that the transient electromagnetic method separates the measurement of H 1 and H2 in time, so it can be used in non-rigid pod systems. However, this method cannot measure the secondary magnetic field in the presence of the primary field.

The aircraft used in airborne electromagnetic method are mainly light fixed-wing aircraft and helicopters suitable for low-altitude flight. The advantages of the former are faster flight speed, longer battery life and lower cost. The disadvantage is that the terrain adaptability is poor, and it is not easy to work in areas with large terrain fluctuations. Helicopters, especially when working with modern jet turbine helicopters, can be effectively used in various terrain conditions. But the speed is slower, the battery life is shorter and the cost is higher.