Patent ID: 6255825
Filing Date: 2001-07-03
Classification: G01V

Abstract:
Apparatus for mapping the ground location of pipelines and wellheads from the air, comprising:first, second and third total magnetic field sensors,a framework adapted to be transported above the ground, the framework comprising a horizontal transverse boom having opposed ends at which are mounted the first and second total magnetic field sensors, a vertical boom extending vertically from the mid-point of the horizontal boom and supporting the third total magnetic sensor at its end remote from said mid-point, and a horizontal, longitudinal boom at right-angles to the transverse and vertical booms and secured thereto, the longitudinal boom having a forward end and a rearward end, a pod at said forward end, and a tail assembly at said rearward end, the tail assembly functioning to maintain the framework in a prescribed orientation relative to the transport direction during flight,altimeter means in said pod, for determining the elevation of the sensors above the ground, andcomputing means for receiving signals from all of the sensors and the altimeter, and for determining magnetic field gradients in three mutually perpendicular directions, by operations based on the received signals.