An approximate relationship between Rps and Rss
Robert R. Stewart, Henry C. Bland
The approximate equations for converted-wave reflectivity Rps and pure-shear reflectivity Rss can be combined to give a simple relationship between the two:
Rps ~= 4(/)sin()Rss(0),
where is the incidence angle of the shear wave. Simple interface examples indicate that the relationship is reasonable up to about a 15 degree angle of incidence. The equation can also be used with P-S data to infer the zero-offset Swave reflectivity.