Abstract: A airborne geophysical electromagnetic (EM) survey tow assembly system for use with an aircraft, including a substantially rigid receiver coil frame that defines a central open area, the receiver coil frame forming a continuous internal passageway that extends around the central open area; a receiver coil housed within the internal passageway isolated from the central open area, the receiver coil being configured to measure the response of surveyed terrain to naturally occurring EM events; and a tow cable for suspending the receiver coil frame from the aircraft, the receiver coil frame being formed from rigid members configured to provide aerodynamic stabilization to maintain the receiver coil frame in a desired pitch and yaw orientation relative to a direction of travel and the horizontal when the receiver coil frame is suspended during flight.

Abstract: A airborne geophysical electromagnetic (EM) survey tow assembly system for use with an aircraft, including a substantially rigid receiver coil frame that defines a central open area, the receiver coil frame forming a continuous internal passageway that extends around the central open area; a receiver coil housed within the internal passageway isolated from the central open area, the receiver coil being configured to measure the response of surveyed terrain to naturally occurring EM events; and a tow cable for suspending the receiver coil frame from the aircraft, the receiver coil frame being formed from rigid members configured to provide aerodynamic stabilization to maintain the receiver coil frame in a desired pitch and yaw orientation relative to a direction of travel and the horizontal when the receiver coil frame is suspended during flight.

Abstract: A airborne geophysical electromagnetic (EM) survey tow assembly system for use with a fixed wing aircraft, including receiver coil assembly comprising a substantially rigid tubular receiver coil frame forming a continuous internal passageway that extends around a central open area, and a receiver coil housed within the internal passageway; a winch system having a tow cable secured to the receiver coil assembly for extending the receiver coil assembly into a survey position; and a latch system for mounting to an underside of the aircraft having releasable latch members for engaging the receiver coil assembly when the receiver coil assembly is in a retracted position.

Abstract: A airborne geophysical electromagnetic (EM) survey tow assembly system for use with a fixed wing aircraft, including receiver coil assembly comprising a substantially rigid tubular receiver coil frame forming a continuous internal passageway that extends around a central open area, and a receiver coil housed within the internal passageway; a winch system having a tow cable secured to the receiver coil assembly for extending the receiver coil assembly into a survey position; and a latch system for mounting to an underside of the aircraft having releasable latch members for engaging the receiver coil assembly when the receiver coil assembly is in a retracted position.