Abstract: The invention is a system designed for acquisition of seismic data by means of acquisition stations set on water bottom of a water body. The system comprises acquisition stations (DSAU) combining a streamlined boom suited to penetrate the bottom and thus couple seismic receivers with the underlying formation, a sealed body for electronic data acquisition and communication modules. These acquisition stations (DSAU) are placed in the water and drop to the bottom under the effect of gravity.

Abstract: A method and device for seismic exploration of a subsea geologic formation by pickups set on the sea bottom and intermittently connectable to active data acquisition stations (11) brought nearby. Permanent passive reception stations (1) comprising a heavy pedestal provided with housings for seismic pickups (geophones (6), hydrophone (7) which receive acoustic or seismic signals from the underlying formation are arranged at the bottom of the water body. When collection sessions for the signals received by the pickups are scheduled, mobile active acquisition stations (11) connected to permanent passive reception stations (1) are positioned at the bottom of the water body. The signals picked up are then recorded, for the time required to carry out at least one session of acquisition and recording of the acoustic or seismic signals received by the passive stations in response to the emission of seismic waves by one or more seismic sources.

Abstract: A method and device for seismic exploration of a subsea geologic formation by pickups set on the sea bottom and intermittently connectable to active data acquisition stations (11) brought nearby. Permanent passive reception stations (1) comprising a heavy pedestal provided with housings for seismic pickups (geophones (6), hydrophone (7)) which receive acoustic or seismic signals from the underlying formation are arranged at the bottom of the water body. When collection sessions for the signals received by the pickups are scheduled, mobile active acquisition stations (11) connected to permanent passive reception stations (1) are positioned at the bottom of the water body. The signals picked up are then recorded, for the time required to carry out at least one session of acquisition and recording of the acoustic or seismic signals received by the passive stations in response to the emission of seismic waves by one or more seismic sources.

Abstract: System designed for acquisition of seismic data by means of acquisition stations set on the bottom of a water mass.

Abstract: A method and system for transferring synchronization data between a central control and seismic recording station and dependent stations in all the cases where the time of transmission through the connection channels between the elements may be liable to too great fluctuations is disclosed. The invention provides a central station (CCU) and intermediate local control and concentration stations (RRS), each connected to local acquisition units (RTU), with a common time reference or clock (H) (that can for example be provided by a satellite positioning network of a well-known type such as the GPS system, or based on the carrier frequency of a radio transmitter) which is picked up by specialized receivers associated with the elements of the seismic device, and in using this common reference to calculate the real transmission time and to local readjust seismic acquisition units (RTU).

Abstract: Transmission method for connecting together a central control and seismic recording station (SCC), local intermediate control and concentration stations (RRS) and local seismic data acquisition, processing and transmission units (RTU).

Abstract: Method and system for transferring synchronization data between a central control and seismic recording station and dependent stations in all the cases where the time of transmission through the connection channels between the elements may be liable to too great fluctuations.

Abstract: The invention pertains to transmission to a remote station, by means of transmission channels (generally radio transmission channels), of seismic data acquired by a data collection equipment comprising a plurality of acquisition units, each being suited to acquire, to store and preferably to compress the data to be transmitted.

Abstract: The invention comprises several groups of local units (BA) suited for the acquisition, the processing and the transmission of data collected in the field by seismic receivers, each of these groups being controlled by a local station (LS) equipped to fulfill extensive functions including collection of the seismic data of the various units, management of testing and initialization operations on radio channels and on the field equipment such as seismic receivers (R), electronics in each unit RTU, monitoring of the progress of seismic operations, and reporting on results and possible anomalies. The seismic set comprises several groups (GR) of receivers, with associated local units and a local station, which are placed under the control of a central synchronization, monitoring and control station (SCC) where all the seismic data are finally gathered. The system is applicable to large-scale seismic exploration.

Abstract: A process is provided for controlling the storage in a recording system of signal samples received successively over a transmission channel. The series of samples to be transmitted are subdivided into blocks comprising a given number of samples and each being provided with a digital timing word and a digital word containing the number of the block. Control units are used for detecting these two words and checking that the number of samples received is conformable and for controlling the access of the data received to the memory.