The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 13, 1990
Filed:
Feb. 21, 1989
Joseph Rialan, Meudon, FR;
Institut Francais du Petrole, Rueil Malmaison, FR;
Abstract
A semi-sequential transmission method and system are provided making it possible for successive groups of seismic acquisition apparatus to communicate simultaneously, using several transmission frequencies, with a central seismic laboratory. Each of said apparatus comprises a frequency synthesizer capable, by means of switches, of setting itself to any one of different frequencies, and means for automatic distribution of the frequencies between the apparatus of the same group. Each of the apparatus, being given an order number dependent on its position along a seismic profile to be studied, determines the difference between its own order number and an order number which it receives by radio and which is that assigned to the first acquisition apparatus of its group. Depending on the difference measured and respecting certain limitations, each acquisition apparatus attributes to itself its own transmission frequency.