*3.2. Calculation of 3D Reflections from a Passive Source Using Direct Migration Based on Geometry*

The process of calculating the 3D reflection from a passive source by using direct migration based on the geometry is similar to the method of generating virtual shot records of reflections from a 3D passive source based on the relevant geometry file, as shown in Figure 18:


**Figure 18.** Processing flow of calculations of the direct migration method for 3D passive seismic exploration.
