Angle formed between a satellite, a ground station, and then another Satellite I am trying to check my work on calculating the angle between two sats and a ground station observing those two sats. I have the az and elevation angles to each sat from the ground station. What would be the equation to get the angle Sat1-GS-Sat2?

I know that it uses the law of Cosines, but not sure if I was using the correct equation.  Here is what I am using:  

Angle = acos((abs(sin("V_Sat_1_EL")*sin("V_Sat_2_EL")))+(cos("V_Sat_1_EL")*cos("V_Sat_2_EL")*cos(abs("V_Sat_2_AZ"-"V_Sat_1_AZ"))))

Thanks
This figure from
Wikipedia:Spherical law of cosines
applies if the ground station is at the center of the sphere, 
u is the ground station's zenith, and v and w are the apparent positions of the satellites as seen from the ground station.



Then a and b are the satellites' zenith angles, i.e. 90&deg; minus their elevation angles.
C is the difference between the satellites' azimuths, and c is the angle you want.

Using the cosine rule for sides
$$\cos c = \cos a \cos b  + \sin a  \sin b  \cos C$$
and the rules for sines and cosines of complementary angles,
the expression in the question looks correct if the absolute value operations are omitted.