  We introduce new estimators of the inhomogeneous $K$-function and the pair
correlation function of a spatial point process as well as the cross
$K$-function and the cross pair correlation function of a bivariate spatial
point process under the assumption of second-order intensity-reweighted
stationarity. These estimators rely on a 'global' normalization factor which
depends on an aggregation of the intensity function, whilst the existing
estimators depend 'locally' on the intensity function at the individual
observed points. The advantages of our new global estimators over the existing
local estimators are demonstrated by theoretical considerations and a
simulation study.
