Data acquisition method and system

A method for acoustically exploring bottom structure of a floor below a water body, the method comprising:

• a) arranging a series of N sensors equidistantly along a streamer, wherein N indicates the number of sensors;
• b) arranging the streamer in the water body in a slanting orientation;
• c) arranging a source for generating acoustic pulses above the streamer, at a horizontal position approximately midway between horizontal positions of a first sensor and a last sensor;
• d) towing the source and the streamer by a common vessel;
• e) actuating the source to produce an acoustic pulse;
• f) using an i-th sensor positioned closer to the vessel than the source to receive a reflection signal and generate a first measurement signal S(i);
• g) displacing the vessel over a distance equal to (N+1-2i)·d/2, wherein d representing a horizontal distance between the sensors;
• h) actuating the source to produce an acoustic pulse;
• i) using the (N+1-i)th sensor to receive a reflection signal and generate a second measurement signal S(N+1-i);
• j) combining the first and second measurement signals to perform a de-ghosting operation and to provide a de-ghosted measuring signal.

A method for acoustically exploring bottom structure of a floor below a water body, the method comprising:

• a) arranging a series of N sensors equidistantly along a streamer, wherein N indicates the number of sensors;
• b) arranging the streamer in the water body in a slanting orientation;
• c) arranging a source for generating acoustic pulses above the streamer, at a horizontal position approximately midway between horizontal positions of a first sensor and a last sensor;
• d) towing the source and the streamer by a common vessel;
• e) actuating the source to produce an acoustic pulse at a predetermined location;
• f) using each sensor to receive a reflection signal and generate a respective measurement signal S(i,x);
• g) receiving and storing the measurement signals S(i,x) from the sensors;
• h) displacing the vessel over a distance equal to d/2, with d representing a horizontal distance between the sensors;
• i) repeating steps e), f), g) and h) at successive increments along a survey profile;
• j) for each signal S(i, x+i−1) obtained from the i-th sensor at a location (x+i−1), selecting the signal S(N+1−i, x+N−i) obtained from the (N+1−i)th sensor at location (x+N−i) to obtain a set of N/2 pairs of matching measurement signals relating to a same reflection point;
• k) for each pair in the set, comparing the matching measurement signals to perform a de-ghosting operation and provide a set of de-ghosted measuring signals relating to same common mid-points.