Page 123 - Acquisition and Processing of Marine Seismic Data

114 2. MARINE SEISMIC DATA ACQUISITION

FIG. 2.68 Geometrical acquisition parameters in (A) side view and (B) plan view for 2D surveys, and (C) for a conventional
3D towed streamer, dual source acquisition.

and 3D survey spreads are illustrated in
Fig. 2.68. TABLE 2.4 Acquisition Parameters Associated With
(ii) Acquisition parameters associated with the the Characteristics of the Recorded Seismic Data
data recording or characteristics of the
recorded seismic data (Table 2.4). Parameter Specification/Relevance/Effect
Record length Target depth and migration
2.5.1 Parameters for Survey Geometry, aperture
Sources, and Receivers Sampling rate Nyquist frequency of the
recorded data
2.5.1.1 Shot Interval
Antialias cut-off Frequency aliasing
Shot interval is the horizontal distance frequencies
between two successive shot points along the
Sample format/dynamic Overall bandwidth of the
seismic lines. In marine seismic acquisition,
range recorded data
recording process continues while the vessel
sails along the seismic profiles with a constant Fold Quality and S/N ratio of the
data
speed as far as possible. Shooting is done at