Changes

Where RNI is the reflection coefficient.

Where RNI is the reflection coefficient.

[[File:Fig.2.normal incidence.jpg|framed|center|Fig.2. Normal Incidence <ref> www.ukm.my </ref>]]

[[File:Fig.2.normal incidence.jpg|framed|center|{{figure number|2|}}Normal Incidence<ref>www.ukm.my</ref>]]

While in the non-normal incidence (fig.3), some of the P-Waves that come will transform into the S waves so that there will be a reflection coefficient variation as a result of different Vp and Vs value. For example, when wave penetrates into a gas layer, the Vp will be decreasing and the Vs will be constant. It means that in certain condition there will be an anomaly in Vp/Vs. This anomaly will cause variation in the reflection coefficient whereas the coefficient itself is the main focus in AVO analysis <ref>Choliq, M. T. (2007). Pemodelan parameter elastic batuan degan inversi AVO untuk karakterisasi reservoir hidrokarbon karbonat formasi baturaja, Jawa Barat Utara.</ref>.  

While in the non-normal incidence (fig.3), some of the P-Waves that come will transform into the S waves so that there will be a reflection coefficient variation as a result of different Vp and Vs value. For example, when wave penetrates into a gas layer, the Vp will be decreasing and the Vs will be constant. It means that in certain condition there will be an anomaly in Vp/Vs. This anomaly will cause variation in the reflection coefficient whereas the coefficient itself is the main focus in AVO analysis <ref>Choliq, M. T., 2007, Pemodelan parameter elastic batuan degan inversi AVO untuk karakterisasi reservoir hidrokarbon karbonat formasi baturaja: Jawa Barat Utara.</ref>.  

[[File:Fig.3.Non-normal incidence.png|framed|center|Fig.3. Non-normal incidence <ref> Stephen,Scott.(2011). University of Indonesia </ref>]]

[[File:Fig.3.Non-normal incidence.png|framed|center|{{figure number|3|}}Non-normal incidence <ref> Stephen,Scott.(2011). University of Indonesia </ref>]]

The relationship between the reflection coefficient and the angle of incidence in write down the Zoeppritz equations by Karl Zoeppritz since the early 20th century and then this equations was developed again by some figures such as Bortfeld (1961), Aki, Richard and Frasier (1976), Hilterman (1983), and Shuey (1985).  

The relationship between the reflection coefficient and the angle of incidence in write down the Zoeppritz equations by Karl Zoeppritz since the early 20th century and then this equations was developed again by some figures such as Bortfeld (1961), Aki, Richard and Frasier (1976), Hilterman (1983), and Shuey (1985).