Inventors:
J. Robert Fort - Altadena CA
James A. Westphal - Altadena CA
Donald R. Juilfs - Chatsworth CA
Assignee:
Geophysical Systems Corporation - Pasadena CA
International Classification:
G01V 134
Abstract:
This abstract describes a system for the field recording of seismic data in which a large plurality of geophones are divided into groups and each group is connected to an array terminal. All of the array terminals are connected in series, by cables, with the last terminal connected to a recording unit. In each of the terminals there are means to process the geophone analog signals by amplifying and adding them to a selected shifting function, and axis-crossing-coding (AXC) the resulting sum signals to provide a plurality of pulses which are stored in a prallel-to-serial converter. In addition, each of the terminals contains a buffer register. On command from the recording unit the bits stored in the converters are read out in series and are transmitted by a pair of signal conductors to the next in series terminal for storage in the buffer register, and from there to the buffer register in the next in series terminal, and so on, until all of the bits stored in each of the terminals are transmitted as a continuing train of single bit signals to the recording unit, where they are recorded on a magnetic disc. Each of the array terminals has a hard wired address code which is transmitted as a heading to the data stored in that converter. Logic circuit means are provided to identify, for each terminal, which of the plurality of cable ports in the terminal are occupied by cables, and which of the cable ports is the one by means of which the commands are received from the recording unit.