Abstract: A geophysical survey method and system that comprises: measuring along multiple axes at multiple locations within a survey area magnetic field components of a low frequency magnetic field resulting from naturally occurring electromagnetic sources using a first sensor system; measuring along multiple axes magnetic field components of a low frequency magnetic field resulting from naturally occurring electromagnetic sources using a second sensor system; and receiving information about the magnetic field components measured by the first sensor system and the second sensor system and in dependence thereon computing parameters from the received information that are independent of rotation of the first sensor system or the second sensor system about any axis thereof.

Abstract: A geophysical survey method and system that comprises: measuring along multiple axes at multiple locations within a survey area magnetic field components of a low frequency magnetic field resulting from naturally occurring electromagnetic sources using a first sensor system; measuring along multiple axes magnetic field components of a low frequency magnetic field resulting from naturally occurring electromagnetic sources using a second sensor system; and receiving information about the magnetic field components measured by the first sensor system and the second sensor system and in dependence thereon computing parameters from the received information that are independent of rotation of the first sensor system or the second sensor system about any axis thereof.

Abstract: An airborne time domain electromagnetic surveying system is provided. The system includes a tow assembly with a flexible support frame. The flexible support frame spaced apart from the aircraft includes a transmitter section with a transmitter loop and a receiver section with a sensor aligned with the central axis of the transmitter section. The flexible support frame has a lightweight modular structure that enables the surface area of the transmitter section to be increased and decreased to suit particular survey applications. The transmitter loop sends a pulse in an “ON” interval, and in an “OFF” interval the sensor measures the earth response to the pulse. The tow assembly also includes a sensor for generating selected survey data in the “ON” interval. A transmitter driver enables the creation of earthbound pulse. The system components are linked to a computer and control computer program linked thereto for controlling the functions thereof.