The only significant word here is "quantum". This stuff is too expensive to be useful for anyone other than the military right now. Gravity maps are controlled information as well. Used for ballistic submarine missiles. The maps created by the military will never be made public. (It would look like a highway of where every vessel is or will be)The accuracy of satellite measurements is 3km, with physical topographic (sea/land) resolution at 1.2km. The long-term plan is to have these sensors traverse areas, record data, and then share it with a database. Even those maps are realistically only 300m~ in resolution. Compare that to GPS, which has a nominal resolution of 3m with 15 satellites, or about a foot, with a correction from ground relays. (I remember using a handheld device that would tell you how many you were connected to, and it stopped working once you were near a tree.) Gravimeters have been used by submarines since the 1980s.

https://en.wikipedia.org/wiki/Gravimetry