FORT BELVOIR, Va. (AP) — Letitia A. Long became the first woman director of a major U.S. intelligence agency Monday, taking her post as chief of the National Geospatial-Intelligence Agency at a ceremony at the agency’s half-built, high-tech campus in Springfield, Va.

Long saluted what the relatively new agency has accomplished, from aiding troops on the battlefield, to helping draw together intelligence from across the national security spectrum.

‘‘I have never seen an agency as young as the NGA do so much in so little time,’’ she said of the organization, which was established in 1996.

She spoke before several hundred VIPs from the intelligence and special ops community on the roof of a parking garage next to her future offices. The ‘‘Jetsons’’-style rounded wedge of buildings is rising from a vast construction site at Fort Belvoir. The NGA’s staff, now spread among several sites across the Washington metropolitan area, is slated to relocate there by fall 2011.

Long’s 32-year career has led to a series of senior management positions: deputy director of Naval Intelligence, deputy undersecretary of defense for intelligence and, most recently, second in command at the Defense Intelligence Agency.

Long’s old boss and mentor, James R. Clapper, newly confirmed as director of national intelligence, noted her 32 years of service, with 16 of them often working in agencies under his purview. Clapper warned her that as soon as he is sworn in as DNI, his ‘‘meddling’’ would continue in her next mission.

Long thanked him for ‘‘taking a chance on a young executive, way back when,’’ and said she welcomed the meddling to come.

Long represents the vanguard of women in the intelligence community.

Women represent 38 percent of total intelligence work force, according to Wendy Morigi, DNI spokeswoman. In six of the most prominent agencies, 27 percent of senior intelligence positions are held by women.

A spokesperson for the NGA, Susan H. Meisner, had identified Long as the first woman to lead one of the nation’s 16 intelligence agencies, but later conceded that women have led smaller intelligence agencies such as the State Department’s intelligence arm.

Long has taken over one of the ‘‘top computer geek shops’’ in the national security world. The NGA synthesizes satellite imagery, using everything from the number of electric lines a city has to the density of the soil, to create three-dimensional, interactive maps of every spot on the planet. They’re used by everyone from invading troops gauging whether a country’s roads or deserts can handle tank tracks, to oil spill cleanup crews trying to decide where to deploy resources.

Long has the science-and-technology credentials to do it, with a degree in electrical engineering from Virginia Tech, and a masters in mechanical engineering from the Catholic University of America. Together with those high powered jobs, Annapolis-born Long and her husband have raised three daughters.

Rep. Anna Eshoo, D-Calif., said Long’s ‘‘experience and position make her an important role model for all the women in the intelligence community.’’ Eshoo is a member of the House intelligence committee and a longtime proponent of women in top intelligence roles.

Some of Long’s new women staffers at the NGA say her example will surely change how the largely male-dominated work force sees them. However, women in their thirties and forties at these agencies say the climb they face is small compared to Long’s fight, against an older generation that hadn’t yet witnessed women in combat or a woman come so close to capturing the nomination for U.S. president.

Yet some of those women out in the national security trenches say the fight’s far from over.

Intelligence executive Carrie Bachner, a former Air Force officer, worked as the legislative adviser to Charles Allen when he was the Department of Homeland Security’s top intelligence official.

That meant she advised him daily on how to deal with the 86 congressional committees responsible for DHS oversight.

Still Bachner says, when she’d walk into a room of officials with Allen, ‘‘they’d automatically ignore me, assuming I was the executive assistant….until they’d realize, ’Oh, wow, she’s the person we’re supposed to talk to.’’’

Bachner says she still experiences that, as president of her own intelligence consulting firm, Mission Concepts Inc. ‘‘They are taken aback when I introduce myself,’’ she said. ‘‘They’re looking for the real president, and well, that’s me.’’