Abstract: A system and method for geolocating an RF emitter disposed on or near the ground includes receiving a signal from the RF emitter at each antenna of an array of N non-collinear antennas, wherein N is an integer greater than 2; routing the signal received at each of the antennas to one of a bank of N corresponding receivers; downconverting the N received signals to N downconverted signals; digitizing the N downconverted signals to digitized signals on N corresponding channels; using a processor to determine phase and amplitude variations across the N channels and to determine a Direction Vector corresponding to the signal received from the RF emitter; using a 2-dimensional pre-determined calibration table to look up a best match to the Direction Vector to determine a Bearing Vector to the RF emitter; transforming the Bearing Vector into locally level reference frame; and geolocating the RF emitter by determining an intersection between the locally level reference frame Bearing Vector and a dataset containing lo

Abstract: A system and method for geolocating an RF emitter disposed on or near the ground includes receiving a signal from the RF emitter at each antenna of an array of N non-collinear antennas, wherein N is an integer greater than 2; routing the signal received at each of the antennas to one of a bank of N corresponding receivers; downconverting the N received signals to N downconverted signals; digitizing the N downconverted signals to digitized signals on N corresponding channels; using a processor to determine phase and amplitude variations across the N channels and to determine a Direction Vector corresponding to the signal received from the RF emitter; using a 2-dimensional pre-determined calibration table to look up a best match to the Direction Vector to determine a Bearing Vector to the RF emitter; transforming the Bearing Vector into locally level reference frame; and geolocating the RF emitter by determining an intersection between the locally level reference frame Bearing Vector and a dataset containing lo

Abstract: The growth of a hydraulic fracture increases the period of free oscillations in the well connected to the fracture. Simultaneously, the decay rate of free oscillations decreases. The properties of forced oscillations in a well also change during fracture growth. All of these effects result from the changing impedance of the hydraulic fracture that intersects the well. Hydraulic fracture impedance can be defined in terms of the hydraulic resistance and the hydraulic capacitance of a fracture. Fracture impedance can be determined directly by measuring the ratio of down hole pressure and flow oscillations or indirectly from well head impedance measurements using impedance transfer functions. Well head pressure measurements can also be used to evaluate fracture impedance by comparing them to pressure oscillations computed with hydraulic models that include fractures with different impedances.

Abstract: The growth of a hydraulic fracture increases the period of free oscillations in the well connected to the fracture. Simultaneously, the decay rate of free oscillations decreases. The properties of forced oscillations in a well also change during fracture growth. All of these effects result from the changing impedance of the hydraulic fracture that intersects the well. Hydraulic fracture impedance can be defined in terms of the hydraulic resistance and the hydraulic capacitance of a fracture. Fracture impedance can be determined directly by measuring the ratio of down hole pressure and flow oscillations or indirectly from well head impedance measurements using impedance transfer functions. Well head pressure measurements can also be used to evaluate fracture impedance by comparing them to pressure oscillations computed with hydraulic models that include fractures with different impedances.