How do I calculate the phase integral for the Bond albedo in astrophysics?

[melkorthefoul]

Hi,

Im doing an IB Extended essay on astrophysics, on the planning stage.

My aim is to calculate the surface temperature of an extrasolar planet.

I have most of the caculations done, but I am stuck on just one part - calculating the Bond albedo of the planet. I know what the geometric albedo is, but how do I calculate the phase integral?

Thanks

P.S
Pls don't just post the formula for the phase integral... pls explain what all of the variables actually stand for

 

[melkorthefoul]

I would really like ANY help I could have :)

 

[melkorthefoul]

Thanks for all of the views, any answers?