Abstract
Conventional marine data is acquired by towed streamers and air-gun sources deployed at small distances below the sea level. A towed hydrophone records both upward travelling waves as well as downward travelling waves including the receiver ghost which reflects from the sea-surface and therefore changes its polarity. Every subsurface reflection is disturbed by the ghost.
Ghost reflections interfere with the primary reflections and distort the frequency spectrum of the recorded seismic data. Spectral notches are introduced at different frequencies depending upon the towed streamer depth, affecting the bandwidth of the data. To minimize the ghost effect least-squares filtering can be applied. However these methods do not introduce any new information and thus do not fundamentally change the poor signal to noise ratio at these notch frequencies.
So in order to suppress the effect of the receiver ghost additional data is needed. This includes acquisition using two streamers placed at different depths or alternatively using a dual-sensor streamer including particle velocity sensors.
The main objective of this thesis is to investigate the performance of different deghosting techniques applied to real data acquired using conventional streamer, over/under towed streamer and dual-sensor streamer.