z⁢(ρ,ϕ)=2⁢π⁢(ρ-1/3⁢u⁡(ϕ)⁢cos⁡(ρ⁢f~⁢(ϕ))⁢Ai⁡(-ρ2/3⁢Δ⁢(ϕ))⁢(1+O⁡(1/ρ))+ρ-2/3⁢v⁡(ϕ)⁢sin⁡(ρ⁢f~⁢(ϕ))⁢Ai′⁡(-ρ2/3⁢Δ⁢(ϕ))⁢(1+O⁡(1/ρ))),