There's a variety of reasons why you might want this quite aside from nuclear missile targeting. For example, gravitational data is used in oil prospecting, something which is important in large swathes of the United States, while precision survey data is obviously useful for such mundane tasks as distinguishing different properties. I would expect that a fairly considerable amount of data, perhaps not precise enough to enable full accuracy but still quite enough to be useful for targeting purposes, could be found in public databases.My understanding is amongst other data required by the computer program(s) that convert the latitude and longitude of the "designated ground zero(s) (ie targets) into guidance commands for the missiles, that gravational data and geodetic survey data are required.