To emphasize his point, Obering testified repeatedly that SBX could see a 3-inch-wide object from across the continent.
“If we place it in Chesapeake Bay, we could actually discriminate and track a baseball-sized object over San Francisco,” he told a Senate subcommittee on April 25, 2007.
Yet because of Earth’s curvature, SBX would not be able to see a baseball at such a distance — about 2,500 miles — unless the ball was 870 or more miles above San Francisco.
That is about 200 miles higher than the expected maximum altitude of a long-range missile headed for the U.S., technical experts told The Times.
“In the practical world of ICBM [inter-continental ballistic missile] threats, this baseball analogy is meaningless,” said C. Wendell Mead, an aerospace engineer who served on the National Academy of Sciences panel.
SBX’s powers of magnification belied a fundamental shortcoming. The radar’s field of vision is extremely narrow: 25 degrees, compared with 90 to 120 degrees for conventional radars.
Experts liken SBX to a soda straw and say that finding a sequence of approaching missiles with it would be impractical.
“It’s an extremely powerful soda straw, but that’s not what we needed,” said Harvey L. Lynch, a physicist who served on the National Academy of Sciences panel.
In the event of an attack, land-based early warning radars could, in theory, identify a specific point in the sky for SBX to focus on. But aiming and re-aiming the giant radar’s beam is a cumbersome manual exercise. In combat conditions, SBX could not be relied on to adjust quickly enough to track a stream of separate missiles, radar specialists said.
SBX’s limitations make it “irrelevant to ballistic missile defense,” said David K. Barton, a physicist and radar engineer who took part in the National Academy review and who has advised U.S. intelligence agencies.
Facebook
Twitter