DTCIG defination | Seiswave Corp

Delayed Time Common Image Gather (DTCIG)

Imaging Condition for reverse time migration(RTM):

Fig 1: RTM produces images on reflectors

RTM only produces images of the reflectors, which are depicted as a green triangles in Figure 1.

Imaging condition for the delayed time gathers (DTCIGs) --- Sava & Fomel, Geophysics, 2006

Different values of τ produce distinct images, which, when combined, result in a delayed time CIG gather as illustrated in Figure 2. The tilted straight lines are created by reflectors, while the central vertical black bar is produced by the diving wave and some of the reflected waves, as depicted in Figures 3 and 4.

Fig 2: a delayed time CIG

Fig 3: RTM generates images along whole diving wave path

Fig 4: RTM creates images along the entire path of reflection waves when the reflectors are accurately positioned