Abstract: A geophysical surveying method and assembly applying transient pulses of electric current to an airborne time-domain electromagnetic transmitter to generate a primary controlled electromagnetic field; measuring, using an airborne receiver, a secondary controlled electromagnetic field to generate controlled field data; measuring, using the airborne receiver, a magnetic component of a natural electromagnetic field at an above-ground position to generate first natural field data; measuring, using a ground receiver at a ground station, telluric electrical currents induced by the natural electromagnetic field and/or a magnetic component of the natural electromagnetic field at a ground position to generate second natural field data; merging the first natural field data and the second natural field data into combined natural field data; extracting, from the combined natural field data, off-time natural field data recorded between the pulses; and generating geophysical survey data based on the controlled field data a

Abstract: An airborne electromagnetic survey system in which a transmitter is airborne and receivers are located at a fixed position or positions on the ground.

Abstract: Various of the disclosed embodiments provide systems and methods to compensate for certain event log errors. For example, when a system fails to record the occurrence of several events (a file closing, a file modification, a network socket opening, etc.) the disclosed embodiments may identify the discrepancy and provide a synthesized event sequence suitable to fulfill the purposes of the event log. In this manner, for example, a client may still be accurately billed for their use of a licensed software or system, even if their usage was punctuated with occasional failures to record their activity.