AUSTRALIA-FIRES/Defense Secretary Robert Gates just proposed cutting the military and security budget  by $78 billion over five years — perhaps only a downpayment on coming further reductions. Secretary Gates’s list of proposed cuts includes high-profile projects and weapons. But he does not mention the National Geospatial-Intelligence Agency, an exemplar of undisciplined spending in the name of defense.

Never heard of the National Geospatial-Intelligence Agency? You’re not alone. A fair guess is that nine of 10 Washington pundits and political insiders don’t know the NGA exists, while perhaps one in 100 can describe its function.

The National Geospatial-Intelligence Agency has 16,000 employees — nearly as many as Google  — and a “black” budget thought to be at least $5 billion per year. The NGA is building a new headquarters complex with the stunning price of $1.8 billion, nearly the cost of the Freedom Tower rising in Manhattan. That new headquarters, near Fort Belvoir, Virginia, will be the third-largest structure in the Washington area, nearly rivaling the Pentagon in size.

The NGA has current touches, possessing a marketing slogan — “Know the Earth, Show the Way” — calling the Defense Department and CIA bureaus that receive its work product “customers” or “partners,” and posting photos of staff receptions on Flickr. But what the National Geospatial-Intelligence Agency does for the most is part classified. About all the agency will say is that it supplies “geospatial intelligence support for global world events” and “can create highly accurate terrain visualization,” phrases that don’t explain much.

This is what the NGA does: take detailed aerial pictures of the Earth’s surface — mainly of cities, including America cities — then overlay them with other forms of data, such as maps of streets and power lines. Think there are drone aircraft only in the skies of Afghanistan and Pakistan? Drone aircraft controlled by the NGA have been crisscrossing the skies of the United States for several years, photographing minute details of roads, houses and campuses. Supposedly this is a counter-terrorism measure: good luck explaining how extremely detailed images of individual homes will deter terrorists. If you were sunbathing nude when an NGA drone passed above your backyard, agency files contain a photo you’ll hope not to see on Flickr.