Ylm(θ,ϕ)=AlmΦm(ϕ)Θlm(θ) Alm=4π(l+m)!(2l+1)(l−m)! Normalization constant Φ(ϕ)=eimϕ Azimuthal angle Θ(θ)=Plm(cosθ) Altitude angle Plm is the associated Legendre polynomial