A source controller distributed system for a multi-element marine source includes a master controller communicating via a cable with source controllers associated with source elements. The master controller generates commands for the source controllers. Each source controller is attached to sensors and mechanisms of one of the source elements, and controls the source element according to the received commands. The source controller also sends data to the master controllers, with the data being gathered by sensors of the source element and/or being related to the status of the source elements, alerts, and/or functional quality control.

A wireless seismic data acquisition unit with a wireless receiver providing access to a common remote time reference shared by a plurality of wireless seismic data acquisition units in a seismic system. The receiver is capable of replicating local version of remote time epoch to which a seismic sensor analog-to-digital converter is synchronized. The receiver is capable of replicating local version of remote common time reference for the purpose of time stamping local node events. The receiver is capable of being placed in a low power, non-operational state over periods of time during which the seismic data acquisition unit continues to record seismic data, thus conserving unit battery power. The system implements a method to correct the local time clock based on intermittent access to the common remote time reference. The method corrects the local time clock via a voltage controlled oscillator to account for environmentally induced timing errors. The invention further provides for a more stable method of correcting drift in the local time clock.

A sensor package may include a sensor housing unit and a first sensor that may acquire a first set of measurements within a first measurement range. The sensor package may also include a second sensor configured to acquire a second set of measurements within a second measurement range. The first measurement range and the second measurement range may include an overlapping range used to calibrate the first set of measurements, the second set of measurements, or both.

A sensor package may include a sensor housing unit and a first sensor that may acquire a first set of measurements within a first measurement range. The sensor package may also include a second sensor configured to acquire a second set of measurements within a second measurement range. The first measurement range and the second measurement range may include an overlapping range used to calibrate the first set of measurements, the second set of measurements, or both.

An electromagnetic induction (EMI) system for characterizing geophysical (e.g. subterranean) environments, includes: (a) a transmitter module including a transmission coil and signal transmission electronics; and (b) at least one receiver module including a receiver coil and signal reception electronics wherein the at least one receiver module is physically separated from the transmitter module without a wired signal connection between them, wherein phase information of signals sent by the transmitter module and those received by at least one receiver module are preserved such that phase information of received signals may be determined and used in characterizing the geophysical environment. In some systems, signal preservation uses a pair of correlated, stable, high frequency clocks.

A multiwell-based interwell logging communication system has a central station and a plurality of satellite stations. The central station has a mobile base station, a central terminal, a ground transmitter for establishing an information transmission link between the central station and each satellite station via broadcast through the mobile base station and the central terminal, a downhole transmitter for receiving a basic beacon signal transmitted from the ground, completing transmission operation in interwell logging based on the basic beacon signal, and realizing communication and control inside a transmitting well in the interwell logging. Each of the satellite stations has a satellite station terminal on the ground, a ground receiver and a downhole receiver. The ground receiver is in point-to-point communication with the ground transmitter through the satellite station terminal so as to control the downhole receiver. The downhole receiver completes reception and collection operations in the interwell logging.