Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN><SPAN>A technique to measure and display the three-dimensional distribution of velocity or </SPAN></SPAN><A href="http://www.glossary.oilfield.slb.com/en/Terms/r/reflectivity.aspx" STYLE="text-decoration:underline;"><SPAN><SPAN>reflectivity</SPAN></SPAN></A><SPAN><SPAN> of a volume of the Earth by using numerous sources and receivers at the Earth's surface. In reflection tomography, space is divided into cells, each having a certain velocity and reflectivity. The final </SPAN></SPAN><A href="http://www.glossary.oilfield.slb.com/en/Terms/m/model.aspx" STYLE="text-decoration:underline;"><SPAN><SPAN>model</SPAN></SPAN></A><SPAN><SPAN> is the one whose velocities and reflectivity’s best describe the data.</SPAN></SPAN></P></DIV></DIV></DIV>