The author considers environmental gravitational noise, but you have to also consider that any movement of the instrument in a non-uniform gravitational field will create a signal. If you consider Earth as a perfect sphere, the gravitational signal of a B-2 that the author considers is equivalent to the change in gravity from a vertical displacement of 0.2nm. This is about the size of a water molecule. Vertical stability at that level is unachievable.
The film caused a minor sensation in the black projects submarine warfare technology community. In one scene, where USS Dallas is chasing Red October through the submarine canyon, the crew can be heard calling out that they have various "milligal anomalies". This essentially revealed the use of gravimetry as a method of silent navigation in US submarines. Thought to be a billion dollar black project, the development of a full-tensor gravity gradiometer by Bell Aerospace was a classified technology at the time. It was thought to be deployed on only a few Ohio-class submarines after it was first developed in 1973.
Good luck, mate.
Real world geophysical gravity measurements are already noise limited by vertical differences of about 1cm (moving w.r.t. the center of mass of the Earth and measuring the mass of the whole planet).
Gradiometry is slightly better, but still. I say build such an instrument first, _then_ try to detect airplanes.
A nuclear submarine can navigate "port to port" entirely on inertial guidance and gravity gradiometry
Failing that, you would want to have your craft look like a heavy truck as much as possible (vibrations should be close to the same period as a common truck suspension, etc) so their denoising algorithms discard you as yet another truck.