I'm a marine spatial ecologist looking to remove land from some kernel density estimations of tagged sharks. I've seen numerous methods for this approach, with one such method described succinctly in Barry & McIntyre (2011):
A typical approach to remedying this [kernel density estimator boundary] problem is first to compute the estimator as if there were no boundaries, then to clip off inaccessible regions after the fact, and finally renormalize the density.
What does it mean to "renormalize" the density? Are they essentially saying that once you calculate the kernel density, you set your boundary areas (in my case, land) to zero, and then make every cell in your kernel range in value from 0 to 1?