“…The pair (r, ϕ) denotes the point with polar coordinates r and ϕ. Note that this definition slightly differs from that of K(r, t) even in the SOIRS stationary and isotropic case, see Ghorbani (2013). The reduced second moment measure K studied in Møller and Toftaker (2012), is given by K(r, t) = K(r, t, 2π) = 2K(r, t, π).…”