I would love if this was designed to take into account elevation data so you could figure out what areas would be shadowed by natural structures like hills.
For example, I'm in Seattle, but on the East side and I expect to be fully shielded from a surface detonation in downtown and to be mostly shielded from air detonation depending on the altitude.
Speaking of air detonations, what altitudes are most nuclear missiles designed to detonate at?