Gravitational waves are ripples in the fabric of spacetime. They are set off by stellar cataclysms such as two black holes colliding, pulsars or neutron stars which are extremely dense stellar objects that have the mass of a sun squished down to the size of a city. To detect these waves, physicists use huge L-shaped optic devices that each arm of which spans four kilometers. There are two of these stations in the United States, one in Washington state and one in Louisiana and collectively they comprise LIGO or the Laser Interferometer Gravitational-Wave Observatory. The LIGO researchers detected a wave that stretched the Earth 1/100,000 of a nanometer; the result of two colossal black holes merging and sending out an invisible explosion out into space stronger than anything humans have ever detected save for the Big Bang. The sensitivity of these instruments can also be applied to communications and navigation. And who is more interested in those two things than the US Military? Gravitational radiation (GR) technology would be ground based and has the potential to replace satellite-based communication systems. The size of these detectors, though, poses a major challenge.
Landsat 2 was an American satellite launched in 1977 as a joint effort between NASA and the Department of the Interior to map the planet and its natural resources. Nations and companies could purchase the images taken by Landsat 2. Chevron did this used them locate oil deposits. The US government also used information from this program to locate and infiltrate mineral reserves in third world countries under the guise of giving them a leg up when in reality they were seeking to further their agenda. Remote sensing is a term used to refer to this practice of gathering data from a distance.
If the military does in fact develop a means of applying gravitational radiation technology to advancing communications, they will have the means to monitor us and increase surveillance without interferences current systems are inhibited by such as weather events and would be less vulnerable to threat activity.