Abstract: A method for controlling timing error in the firing of an idle seismic air gun comprises the steps of identifying an acceptable range of seismic air gun timing error, and identifying a relationship between seismic air gun timing error and an idle period preceding a seismic air gun firing event. The first firing event time following an idle period is then compensated according to the identified relationship to control the timing error within the identified acceptable range. The invention may be implemented using computer means such as machine-readable storage media. The invention may be applied to advantage when air gun firing delays are experienced, such as during selective changes from one air gun group to another air gun group for purposes of achieving a desired center-of-source position.

Abstract: Marine seismic survey systems and methods are presented. One system comprises a source array, a tow vessel, one or more source tow members, one or more deflecting members operatively connected to the source array; one or more streamers connected to the tow vessel by a corresponding number of streamer tow members, one or more of the streamers positioned by corresponding one or more active or passive streamer deflectors, one or more source separation members connecting one or more source tow members to one or more streamer tow members, and optionally one or more streamer separation members connecting one or more streamer tow members. The one or more source separation members help position the source array in conjunction with the one or more. deflecting members. This abstract complies with rules requiring an abstract. It should not be used to limit the scope or meaning of the claims. 37 CFR 1.72(b).