Figure 2.
Mapping of the ϕ, ψ plane onto the θ, α plane. Left: lines ϕ−ψ =cost are represented in different colors. Right: The same lines are mapped onto the α, θ plane. The region that they define is the image of the whole ϕ, ψ plane onto the α, θ plane through the (ϕ, ψ) → (α, θ) map. Some relevant points are reported.